Oil supplementing control method and device of excavator hydraulic system, excavator and storage medium

Abstract

The invention relates to the technical field of excavators, and particularly discloses an oil supplementing control method and device of an excavator hydraulic system, an excavator and a storage medium. The oil supplementing control method of the excavator hydraulic system comprises the steps that the required flow of a movable arm oil cylinder, the required flow of a bucket rod oil cylinder and the required flow of a bucket oil cylinder are obtained; determining the required rotating speed of an oil supplementing pump based on the required flow of the movable arm oil cylinder, the required flow of the bucket rod oil cylinder and the required flow of the bucket oil cylinder; the oil recharging pump operates at the required rotating speed; the current pressure of an oil supplementing oil way is obtained; calculating a difference value between the set pressure and the current pressure; judging the difference value and a set value; and when the difference value is larger than the set value, the rotating speed of the oil supplementing pump is increased by the set rotating speed on the current basis, the step of obtaining the current pressure of the oil supplementing oil way is returned, the rotating speed of the oil supplementing pump can be made to be matched with the total flow required by the three oil cylinders, and it can be guaranteed that the oil supplementing oil way can stably supplement oil to the oil way where the three oil cylinders are located.

Description

Technical Field

[0001] The present invention relates to the technical field of excavators, and in particular to an oil replenishment control method and device for an excavator hydraulic system, an excavator and a storage medium. Background Art

[0002] The main movements of the hydraulic excavator include the movement of the whole machine (left movement, right movement), platform rotation, and the movement of the boom, dipper arm and bucket of the working device. The main movement performance of the hydraulic excavator includes excavation performance, loading performance, leveling performance, etc., which requires a good coordination relationship between the various movements, that is, controllability.

[0003] In the prior art, each actuator of the hydraulic system of the excavator is usually decoupled and supplied with oil separately, so as to eliminate the energy waste caused by load coupling when the multiple actuators of the excavator perform compound actions, and improve the operability of each actuator. After the actuator is decoupled, an open hydraulic system or a closed hydraulic system can be used for oil supply. When a closed hydraulic system is used for oil supply, the oil supply circuit is supplemented with oil by the oil supply pump, and the oil supply circuit supplements the low-pressure oil circuit of the closed hydraulic system. The excess oil in the oil supply circuit overflows through the oil supply overflow valve, and the excess oil in the high-pressure oil circuit of the closed hydraulic system overflows through the high-pressure overflow valve. Among them, when the oil supply pump is working, the oil supply pump is usually started and stopped based on the oil pressure of the oil supply circuit. After the oil supply pump is turned on, it usually runs at the rated speed. The rated speed is usually set relatively high to ensure that the oil pressure of the oil supply circuit remains stable, which also causes too much oil to overflow from the oil supply overflow valve, resulting in energy waste; at the same time, the high-pressure overflow of the high-pressure oil circuit will cause the oil temperature to rise and affect the thermal balance of the system. Summary of the invention

[0004] The purpose of the present invention is to provide an oil replenishment control method and device for an excavator hydraulic system, an excavator and a storage medium, so as to solve the problem in the prior art that energy waste is easily caused when the oil replenishment pump of the excavator hydraulic system is started.

[0005] In a first aspect, the present invention provides an oil replenishment control method for an excavator hydraulic system, wherein the excavator hydraulic system comprises a first closed hydraulic system, a second closed hydraulic system, a third closed hydraulic system and an oil replenishment pump, wherein the first closed hydraulic system is used to drive a boom cylinder to move, the second closed hydraulic system is used to drive a dipper cylinder to move, the third closed hydraulic system is used to drive a bucket cylinder to move, and both ends of the oil replenishment pump are respectively connected to an oil tank and an oil replenishment oil circuit, and the oil replenishment oil circuit is used to supply oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system; the oil replenishment control method for the excavator hydraulic system comprises:

[0006] Obtain the required flow of the boom cylinder, the arm cylinder and the bucket cylinder;

[0007] Determining a required rotation speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the arm cylinder, and the required flow of the bucket cylinder;

[0008] The oil charge pump operates at a required speed;

[0009] Get the current pressure of the oil replenishment circuit;

[0010] Calculating the difference between the set pressure and the current pressure;

[0011] Determine the size of the difference and the set value;

[0012] If the difference is greater than the set value, the speed of the oil replenishment pump is increased to the set speed based on the current speed and the process returns to the step of obtaining the current pressure of the oil replenishment circuit.

[0013] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the first closed hydraulic system includes a first boom oil pump, a second boom oil pump and a boom balancing valve, one end of the first boom oil pump is connected to the first boom oil circuit, and the other end is connected to the second boom oil circuit, the first boom oil circuit is connected to the boom rodless chamber of the boom oil cylinder, the second boom oil circuit is connected to the boom rod chamber of the boom oil cylinder, the boom balancing valve is configured to connect the one with smaller oil pressure of the first boom oil circuit and the second boom oil circuit to the oil replenishment circuit, one end of the second boom oil pump is connected to the oil replenishment circuit, the other end of the second boom oil pump is connected to the third boom oil circuit, and the third boom oil circuit is connected to the first boom oil circuit;

[0014] Obtaining the required flow of the boom cylinder includes:

[0015] Obtaining the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve;

[0016] The required flow rate of the boom cylinder is determined based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve.

[0017] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the excavator includes a joystick, and the joystick is used to control the extension and retraction of the boom piston rod of the boom cylinder;

[0018] Obtaining the required flow of the boom cylinder includes:

[0019] Obtaining the position of the joystick;

[0020] Determining a movement direction of a boom piston rod of the boom cylinder and a movement speed of the boom piston rod of the boom cylinder based on the position of the operating handle;

[0021] Obtain the area of ​​the boom rod chamber of the boom cylinder and the area of ​​the boom rodless chamber of the boom cylinder;

[0022] The required flow of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod of the boom cylinder, the area of ​​the boom rod chamber of the boom cylinder and the area of ​​the boom rodless chamber of the boom cylinder.

[0023] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the second closed hydraulic system includes a first boom oil pump, a second boom oil pump and a boom balancing valve, one end of the first boom oil pump is connected to the first boom oil circuit, and the other end is connected to the second boom oil circuit, the first boom oil circuit is connected to the boom rodless chamber of the boom cylinder, the second boom oil circuit is connected to the boom rod chamber of the boom cylinder, the boom balancing valve is configured to connect the one with smaller oil pressure of the first boom oil circuit and the second boom oil circuit to the oil replenishment circuit, one end of the second boom oil pump is connected to the oil replenishment circuit, the other end of the second boom oil pump is connected to the third boom oil circuit, and the third boom oil circuit is connected to the first boom oil circuit;

[0024] Obtaining the required flow of the boom cylinder includes:

[0025] Obtaining the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve;

[0026] The required flow rate of the boom cylinder is determined based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve.

[0027] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the excavator includes a joystick, and the joystick is used to control the extension and retraction of the bucket rod piston rod of the bucket rod cylinder;

[0028] Obtaining the required flow of the boom cylinder includes:

[0029] Obtaining the position of the joystick;

[0030] Determining the direction of movement of the boom piston rod and the speed of movement of the boom piston rod based on the position of the control handle;

[0031] Obtaining the area of ​​the arm cavity of the arm cylinder and the area of ​​the rodless cavity of the arm of the arm cylinder;

[0032] The required flow of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity and the area of ​​the boom rodless cavity of the boom cylinder.

[0033] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the third closed hydraulic system includes a first bucket oil pump, a second bucket oil pump and a bucket balancing valve, one end of the first bucket oil pump is connected to the first bucket oil circuit, and the other end is connected to the second bucket oil circuit, the first bucket oil circuit is connected to the bucket rodless chamber of the bucket cylinder, and the second bucket oil circuit is connected to the bucket rod chamber of the bucket cylinder, and the bucket balancing valve is configured to connect the one with the smaller oil pressure of the first bucket oil circuit and the second bucket oil circuit to the oil replenishment oil circuit, one end of the second bucket oil pump is connected to the oil replenishment oil circuit, and the other end of the second bucket oil pump is connected to the third bucket oil circuit, and the third bucket oil circuit is connected to the first bucket oil circuit;

[0034] Obtaining the required flow of the bucket cylinder includes:

[0035] Obtaining the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve;

[0036] A required flow rate of the bucket cylinder is determined based on a flow rate of the oil flowing through the second bucket oil pump and a flow rate of the oil flowing through the bucket balance valve.

[0037] As a preferred technical solution of the oil replenishment control method of the hydraulic system of the excavator, the excavator includes a joystick, and the joystick is used to control the extension and retraction of the bucket piston rod of the bucket cylinder;

[0038] Obtaining the required flow of the bucket cylinder includes:

[0039] Obtaining the position of the joystick;

[0040] Determining a movement direction of a bucket piston rod of the bucket cylinder and a movement speed of the bucket piston rod of the bucket cylinder based on the position of the joystick;

[0041] Obtain the area of ​​the bucket rod cavity of the bucket cylinder and the area of ​​the bucket rodless cavity of the bucket cylinder;

[0042] The required flow of the bucket cylinder is determined based on the movement direction of the bucket piston rod, the movement speed of the bucket piston rod of the bucket cylinder, the area of ​​the bucket rod cavity of the bucket cylinder and the area of ​​the bucket rodless cavity of the bucket cylinder.

[0043] In a second aspect, the present invention provides an oil replenishment control device for an excavator hydraulic system, wherein the excavator hydraulic system comprises a first closed hydraulic system, a second closed hydraulic system, a third closed hydraulic system and an oil replenishment pump, wherein the first closed hydraulic system is used to drive the boom cylinder to move, the second closed hydraulic system is used to drive the dipper rod cylinder to move, and the third closed hydraulic system is used to drive the bucket cylinder to move, and the two ends of the oil replenishment pump are respectively connected to an oil tank and an oil replenishment oil circuit, and the oil replenishment oil circuit is used to supply oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system; the oil replenishment control device for the excavator hydraulic system comprises:

[0044] A flow acquisition module is used to acquire the required flow of the boom cylinder, the required flow of the arm cylinder and the required flow of the bucket cylinder;

[0045] A required speed determination module, used to determine the required speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the dipper cylinder and the required flow of the bucket cylinder;

[0046] An execution module, used for making the oil charge pump run at a required speed;

[0047] A current pressure acquisition module is used to obtain the current pressure of the oil replenishment circuit;

[0048] A difference calculation module, used for calculating the difference between the set pressure and the current pressure;

[0049] A judgment module is used to judge the difference between the difference value and the set value;

[0050] The speed increasing module is used to increase the speed of the oil replenishment pump by a set speed based on the current speed when the difference is greater than a set value.

[0051] In a third aspect, the present invention provides an excavator, comprising:

[0052] one or more processors;

[0053] A storage device for storing one or more programs;

[0054] When the one or more programs are executed by the one or more processors, the one or more processors control the excavator to implement the oil replenishment control method of the excavator hydraulic system as described in any of the above solutions.

[0055] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, enables an excavator to implement the oil replenishment control method for an excavator hydraulic system as described in any of the above-mentioned schemes.

[0056] The beneficial effects of the present invention are as follows:

[0057] The invention provides an oil replenishment control method, device, excavator and storage medium for the hydraulic system of an excavator. The oil replenishment control method for the hydraulic system of the excavator obtains the required flow of the boom cylinder, the required flow of the arm cylinder and the required flow of the bucket cylinder, and determines the required speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the arm cylinder and the required flow of the bucket cylinder; the oil replenishment pump runs at the required speed; obtains the current pressure of the oil replenishment circuit; calculates the difference between the set pressure and the current pressure; judges the size of the difference and the set value; when the difference is greater than the set value: increases the speed of the oil replenishment pump by the set speed on the current basis and returns to the step of obtaining the current pressure of the oil replenishment circuit, so that the speed of the oil replenishment pump can match the total flow required by the boom cylinder, the bucket cylinder and the arm cylinder, avoids the oil replenishment pump speed being too high, resulting in energy waste, and the speed of the oil replenishment pump can also ensure that the oil pressure of the oil replenishment circuit stably replenishes oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a first structural schematic diagram of the hydraulic system of the excavator in an embodiment of the present invention;

[0059] Figure 2 A second structural schematic diagram of the hydraulic system of the excavator in an embodiment of the present invention;

[0060] Figure 3 A third structural schematic diagram of the hydraulic system of an excavator in an embodiment of the present invention;

[0061] Figure 4 Flow chart of the oil replenishment control method of the hydraulic system of the excavator in the embodiment of the present invention;

[0062] Figure 5 Schematic diagram of the structure of the oil replenishment control device of the hydraulic system of the excavator in the embodiment of the present invention;

[0063] Figure 6 It is a structural schematic diagram of a control system of an excavator hydraulic system provided by an embodiment of the present invention.

[0064] In the figure:

[0065] 1. Boom cylinder; 2. Arm cylinder; 3. Bucket cylinder; 4. Oil replenishment pump; 5. Fuel tank; 6. Oil replenishment circuit; 7. Oil replenishment overflow valve; 8. First boom oil pump; 9. Boom balance valve; 10. First boom oil circuit; 11. Second boom oil circuit; 12. Second boom oil pump; 13. Third boom oil circuit; 14. Hydraulic control valve group; 15. First hydraulic control check valve; 16. Boom control valve; 17. First oil replenishment check valve; 18. Second oil replenishment check valve; 19. First overflow valve; 20. Second overflow valve; 21. First boom oil pump; 22. Boom balance valve; 23. First boom oil circuit; 24. Second boom oil circuit; 25. Second boom oil pump; 26. First 3. Arm oil circuit; 27. 2nd hydraulically controlled one-way valve; 28. 3rd hydraulically controlled one-way valve; 29. ​​Arm control valve; 30. 3rd oil replenishment one-way valve; 31. 4th oil replenishment one-way valve; 32. 3rd overflow valve; 33. 4th overflow valve; 34. Arm regeneration valve; 35. 1st bucket oil pump; 36. Bucket balance valve; 37. 1st bucket oil circuit; 38. 2nd bucket oil circuit; 39. 2nd bucket oil pump; 40. 3rd bucket oil circuit; 41. 4th hydraulically controlled one-way valve; 42. 5th hydraulically controlled one-way valve; 43. Bucket control valve; 44. 5th oil replenishment one-way valve; 45. 6th oil replenishment one-way valve; 46. 5th overflow valve; 47. 6th overflow valve; 48. Bucket regeneration valve;

[0066] 50. Flow acquisition module; 51. Required speed determination module; 52. Execution module; 53. Current pressure acquisition module; 54. Difference calculation module; 55. Judgment module; 56. Speed ​​increase module;

[0067] 100, terminal device; 110, processor; 120, ROM; 130, RAM; 140, bus; 150, I / O interface; 160, input unit; 170, output unit; 180, storage unit; 190, communication unit. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0070] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0072] The present embodiment provides an oil replenishment control method for an excavator hydraulic system. The oil replenishment control method for an excavator hydraulic system is suitable for automatically controlling an oil replenishment pump. The oil replenishment control method for an excavator hydraulic system can be executed by an oil replenishment control device for the excavator hydraulic system. The oil replenishment control device for the excavator hydraulic system can be implemented by software and / or hardware and integrated in the excavator.

[0073] Please refer to Figures 1 to 3The hydraulic system of the excavator includes a first closed hydraulic system, a second closed hydraulic system, a third closed hydraulic system and an oil replenishment pump 4. The first closed hydraulic system is used to drive the boom cylinder 1 to move, the second closed hydraulic system is used to drive the dipper rod cylinder 2 to move, and the third closed hydraulic system is used to drive the bucket cylinder 3 to move. The two ends of the oil replenishment pump 4 are respectively connected to the oil tank 5 and the oil replenishment circuit 6. The oil replenishment circuit 6 is used to supply oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system. In this way, the boom cylinder 1, the dipper rod cylinder 2 and the bucket cylinder 3 are decoupled respectively, which is convenient for controlling the boom, the dipper rod and the bucket.

[0074] The excavator hydraulic system further includes an oil replenishment overflow valve 7 connected to the oil replenishment oil circuit 6 , and the oil replenishment overflow valve 7 is used to overflow the oil in the oil replenishment oil circuit 6 that exceeds the set pressure to the oil tank 5 .

[0075] Please refer to Figure 1 In this embodiment, the boom cylinder 1 includes a boom rod chamber and a boom rodless chamber with variable volumes. The boom cylinder 1 also includes a boom piston rod and a boom cylinder body. The boom piston rod divides the inner chamber of the boom cylinder body into a boom rod chamber and a boom rodless chamber. The boom piston rod passes through the boom rod chamber so that the cross-sectional area of ​​the boom rod chamber is smaller than the cross-sectional area of ​​the boom rodless chamber. The boom piston rod can move in the boom cylinder body, and when the boom piston rod moves, the volumes of the boom rod chamber and the boom rodless chamber increase and decrease. In this embodiment, the boom cylinder body is hinged to the excavator body, and the boom piston rod is hinged to the boom.

[0076] Optionally, the first closed hydraulic system includes a first boom oil pump 8, a second boom oil pump 12 and a boom balancing valve 9, one end of the first boom oil pump 8 is connected to the first boom oil circuit 10, and the other end is connected to the second boom oil circuit 11, the first boom oil circuit 10 is connected to the boom rodless chamber of the boom cylinder 1, and the second boom oil circuit 11 is connected to the boom rod chamber of the boom cylinder 1, and the boom balancing valve 9 is configured to connect the one with the smaller oil pressure between the first boom oil circuit 10 and the second boom oil circuit 11 to the oil replenishing circuit 6, one end of the second boom oil pump 12 is connected to the oil replenishing circuit 6, and the other end of the second boom oil pump 12 is connected to the third boom oil circuit 13, and the third boom oil circuit 13 is connected to the first boom oil circuit 10. Since the cross-sectional areas of the boom rod chamber and the boom rodless chamber are different, there is a flow difference. When the first boom oil pump 8 drives the oil to flow between the boom rod chamber and the boom rodless chamber, the second boom oil pump 12 can drive the oil to flow between the oil replenishment circuit 6 and the boom rodless chamber, and the boom balance valve 9 connects the one with the smaller oil pressure of the first boom oil circuit 10 and the second boom oil circuit 11 to the oil replenishment circuit 6 to balance the flow difference between the boom rod chamber and the boom rodless chamber. In addition, the oil temperature in the oil replenishment circuit 6 is relatively low, and the hot oil in the boom hydraulic circuit can be replaced with the low-temperature oil in the oil replenishment circuit, which can ensure the normal oil temperature in the boom hydraulic circuit, and thus ensure the normal operation of the boom cylinder 1. Among them, the first boom oil pump 8 and the second boom oil pump 12 are both closed pumps. The first boom oil pump 8 can rotate forward and reverse, and the second boom oil pump 12 can also rotate forward and reverse. Specifically, both the first boom oil pump 8 and the second boom oil pump 12 may be quantitative pumps.

[0077] Among them, the movement direction of the piston rod and the direction of the load force on the piston rod jointly determine the oil pressure in the rodless chamber and the rod chamber. When the direction of the load force is consistent with the movement direction of the piston rod, the load force is a negative load. When the direction of the load force is opposite to the movement direction of the piston rod, the load force is a positive load.

[0078] When the boom piston rod moves to the extended position, the boom piston rod gradually extends outward, the first boom oil pump 8 rotates forward, and pumps the oil in the boom rod chamber to the boom rodless chamber. If the boom piston rod is under positive load at this time, the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber, then the boom balancing valve 9 connects the second boom oil circuit 11 and the oil replenishing circuit 6. If the boom piston rod is under negative load at this time, the oil pressure in the boom rod chamber is greater than the oil pressure in the boom rodless chamber, then the boom balancing valve 9 connects the first boom oil circuit 10 and the oil replenishing circuit 6. When the boom piston rod moves to the retracted position, the boom piston rod gradually retracts inward. If the boom piston rod is subjected to a positive load at this time, the oil pressure in the boom rod chamber is greater than the oil pressure in the boom rodless chamber, then the boom balancing valve 9 connects the first boom oil circuit 10 and the oil replenishing circuit 6. If the boom piston rod is subjected to a negative load at this time, the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber, then the boom balancing valve 9 connects the second boom oil circuit 11 and the oil replenishing circuit 6.

[0079] In the present embodiment, the boom balancing valve 9 is a hydraulically controlled valve, and the boom balancing valve 9 has a hydraulic control end A1 and a hydraulic control end A2. The hydraulic control end A1 is connected to the first boom oil circuit 10, and the hydraulic control end A2 is connected to the second boom oil circuit 11. The hydraulic control end A1 and the hydraulic control end A2 are respectively located on both sides of the valve core of the boom balancing valve 9, and the oil of the hydraulic control end A1 and the hydraulic control end A2 directly acts on the valve core of the boom balancing valve 9. The force of the oil of the hydraulic control end A1 acting on the valve core of the boom balancing valve 9 and the force of the oil of the hydraulic control end A2 acting on the valve core of the boom balancing valve 9 are compared to determine the stop position of the valve core of the boom balancing valve 9. Among them, the boom balancing valve 9 has a left position, a right position and a middle position. When the boom balancing valve 9 is in the left position, the boom balancing valve 9 connects the oil supply circuit 6 and the second boom oil circuit 11; when the boom balancing valve 9 is in the right position, the boom balancing valve 9 connects the oil supply circuit 6 and the first boom oil circuit 10; when the boom balancing valve 9 is in the middle position, the first boom oil circuit 10 and the second boom oil circuit 11 are both disconnected from the oil supply circuit 6.

[0080] In this embodiment, the first closed hydraulic system also includes a first hydraulically controlled one-way valve 15, wherein the first hydraulically controlled one-way valve 15 is arranged on the first boom oil circuit 10. When the oil pressure of the oil delivered to the first hydraulically controlled one-way valve 15 exceeds the set value, the first hydraulically controlled one-way valve 15 can be opened, and the oil continues to be delivered to the boom rodless chamber; when the oil pressure of the oil delivered to the first hydraulically controlled one-way valve 15 does not exceed the set value, the first hydraulically controlled one-way valve 15 disconnects the first boom oil circuit 10. At this time, the first hydraulically controlled one-way valve 15 can be controlled to open or close by the hydraulically controlled valve group 14 of the first hydraulically controlled one-way valve 15. The specific structure of the first hydraulically controlled one-way valve 15 is a prior art and will not be described in detail here.

[0081] The first closed hydraulic system also includes a boom control valve 16, which is arranged in the first boom oil circuit 10 and is located between the connection between the third boom oil circuit 13 and the first boom oil circuit 10 and the first boom oil pump 8. The boom control valve 16 is used to open or close the first boom oil circuit 10.

[0082] The first closed hydraulic system further includes a first oil replenishment check valve 17 and a second oil replenishment check valve 18. The first oil replenishment check valve 17 is connected between the oil replenishment oil circuit 6 and the first boom oil circuit 10, and the first oil replenishment check valve 17 only allows oil to flow from the oil replenishment oil circuit 6 to the first boom oil circuit 10. The second oil replenishment check valve 18 only allows oil to flow from the oil replenishment oil circuit 6 to the second boom oil circuit 11.

[0083] The first closed hydraulic system also includes a first overflow valve 19 and a second overflow valve 20. The first overflow valve 19 is connected between the oil replenishing circuit 6 and the first boom oil circuit 10, and the first overflow valve 19 only allows oil to overflow from the boom rodless chamber through the first boom oil circuit 10 to the oil replenishing circuit 6. The second overflow valve 20 is connected between the oil replenishing circuit 6 and the second boom oil circuit 11, and the second overflow valve 20 only allows oil to overflow from the boom rod chamber through the second boom oil circuit 11 to the oil replenishing circuit 6.

[0084] Please refer to Figure 2 The arm oil cylinder 2 includes an arm rod chamber and an arm rodless chamber with variable volumes. The arm oil cylinder 2 also includes an arm piston rod and an arm cylinder body. The arm piston rod divides the inner chamber of the arm cylinder body into an arm rod chamber and an arm rodless chamber. The arm piston rod passes through the arm rod chamber so that the cross-sectional area of ​​the arm rod chamber is smaller than the cross-sectional area of ​​the arm rodless chamber. The arm piston rod can move in the arm cylinder body, and when the arm piston rod moves, the volumes of the arm rod chamber and the arm rodless chamber increase and decrease. In this embodiment, the arm cylinder body is hinged to the boom, and the arm piston rod is hinged to the arm.

[0085] Optionally, the second closed hydraulic system includes a first boom oil pump 21, a second boom oil pump 25 and a boom balancing valve 22, one end of the first boom oil pump 21 is connected to the first boom oil circuit 23, and the other end is connected to the second boom oil circuit 24, the first boom oil circuit 23 is connected to the boom rodless chamber of the boom cylinder 2, the second boom oil circuit 24 is connected to the boom rod chamber of the boom cylinder 2, the boom balancing valve 22 is configured to connect the one with the smaller oil pressure between the first boom oil circuit 23 and the second boom oil circuit 24 to the oil replenishment circuit 6, one end of the second boom oil pump 25 is connected to the oil replenishment circuit 6, the other end of the second boom oil pump 25 is connected to the third boom oil circuit 26, and the third boom oil circuit 26 is connected to the first boom oil circuit 23. Since the cross-sectional areas of the boom cavity and the boom cavity are different, there is a flow difference. When the first boom oil pump 21 drives the oil to flow between the boom cavity and the boom cavity, the second boom oil pump 25 can drive the oil to flow between the oil supply circuit 6 and the boom cavity, and the boom balance valve 22 connects the first boom oil circuit 23 and the second boom oil circuit 24 with the oil supply circuit 6, which has a smaller oil pressure, to balance the flow difference between the boom cavity and the boom cavity. The oil temperature in the oil supply circuit 6 is relatively low, and the hot oil in the boom hydraulic circuit can be replaced with the low-temperature oil in the oil supply circuit, which can ensure the normal oil temperature in the boom hydraulic circuit and thus ensure the normal operation of the boom cylinder 2. Among them, the first boom oil pump 21 and the second boom oil pump 25 are both closed pumps. The first boom oil pump 21 can rotate forward and reverse, and the second boom oil pump 25 can also rotate forward and reverse. Specifically, both the first boom oil pump 21 and the second boom oil pump 25 may be quantitative pumps.

[0086] When the boom piston rod moves to the extended position, the boom piston rod gradually extends outward, the first boom oil pump 21 rotates forward, and pumps the oil in the boom rod chamber to the boom rodless chamber. If the boom piston rod is under positive load at this time, the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber, then the boom balance valve 22 connects the second boom oil circuit 24 and the oil replenishing circuit 6. If the boom piston rod is under negative load at this time, the oil pressure in the boom rod chamber is greater than the oil pressure in the boom rodless chamber, then the boom balance valve 22 connects the first boom oil circuit 23 and the oil replenishing circuit 6. When the boom piston rod moves to the retracted position, the boom piston rod gradually retracts inward. If the boom piston rod is subjected to a positive load at this time, and the oil pressure in the boom rod chamber is greater than the oil pressure in the boom rodless chamber, the boom balance valve 22 connects the first boom oil circuit 23 and the oil replenishing circuit 6. If the boom piston rod is subjected to a negative load at this time, and the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber, the boom balance valve 22 connects the second boom oil circuit 24 and the oil replenishing circuit 6.

[0087] In this embodiment, the boom balancing valve 22 is a hydraulically controlled valve, and the boom balancing valve 22 has a hydraulic control end A3 and a hydraulic control end A4. The hydraulic control end A3 is connected to the first boom oil circuit 23, and the hydraulic control end A4 is connected to the second boom oil circuit 24. The hydraulic control end A3 and the hydraulic control end A4 are respectively located on both sides of the valve core of the boom balancing valve 22, and the oil of the hydraulic control end A3 and the hydraulic control end A4 directly acts on the valve core of the boom balancing valve 22. The force of the oil of the hydraulic control end A3 acting on the valve core of the boom balancing valve 22 and the force of the oil of the hydraulic control end A4 acting on the valve core of the boom balancing valve 22 are compared to determine the stop position of the valve core of the boom balancing valve 22. Among them, the boom balancing valve 22 has a left position, a right position and a middle position. When the boom balancing valve 22 is in the left position, the boom balancing valve 22 connects the oil supply circuit 6 and the second boom oil circuit 24; when the boom balancing valve 22 is in the right position, the boom balancing valve 22 connects the oil supply circuit 6 and the first boom oil circuit 23; when the boom balancing valve 22 is in the middle position, the first boom oil circuit 23 and the second boom oil circuit 24 are both disconnected from the oil supply circuit 6.

[0088] In this embodiment, the second closed hydraulic system also includes a second hydraulically controlled one-way valve 27 and a third hydraulically controlled one-way valve 28, wherein the second hydraulically controlled one-way valve 27 is arranged on the first boom oil circuit 23. When the oil pressure of the oil delivered to the second hydraulically controlled one-way valve 27 exceeds the set value, the second hydraulically controlled one-way valve 27 can be opened, and the oil continues to be delivered to the boom rodless chamber; when the oil pressure of the oil delivered to the second hydraulically controlled one-way valve 27 does not exceed the set value, the second hydraulically controlled one-way valve 27 disconnects the first boom oil circuit 23. At this time, the second hydraulically controlled one-way valve 27 can be controlled to open or close by the hydraulically controlled valve group of the second hydraulically controlled one-way valve 27. The third hydraulically controlled one-way valve 28 is arranged on the second boom oil circuit 24. When the oil pressure of the oil delivered to the third hydraulically controlled one-way valve 28 exceeds the set value, the third hydraulically controlled one-way valve 28 can be opened, and the oil continues to be delivered to the boom rod chamber; when the oil pressure of the oil delivered to the third hydraulically controlled one-way valve 28 does not exceed the set value, the third hydraulically controlled one-way valve 28 disconnects the second boom oil circuit 24. At this time, the third hydraulically controlled one-way valve 28 can be controlled to open or close by the hydraulically controlled valve group of the third hydraulically controlled one-way valve 28. The specific structures of the second hydraulically controlled one-way valve 27 and the third hydraulically controlled one-way valve 28 are prior art and will not be described in detail here.

[0089] The second closed hydraulic system also includes an arm control valve 29, which is arranged in the first arm oil circuit 23 and is located between the connection between the third arm oil circuit 26 and the first arm oil circuit 23 and the first arm oil pump 21. The arm control valve 29 is used to open or close the first arm oil circuit 23.

[0090] The second closed hydraulic system further includes a third oil replenishment check valve 30 and a fourth oil replenishment check valve 31. The third oil replenishment check valve 30 is connected between the oil replenishment oil circuit 6 and the first boom oil circuit 23, and the third oil replenishment check valve 30 only allows oil to flow from the oil replenishment oil circuit 6 to the first boom oil circuit 23. The fourth oil replenishment check valve 31 only allows oil to flow from the oil replenishment oil circuit 6 to the second boom oil circuit 24.

[0091] The second closed hydraulic system also includes a third overflow valve 32 and a fourth overflow valve 33. The third overflow valve 32 is connected between the oil replenishing circuit 6 and the first boom oil circuit 23, and the third overflow valve 32 only allows oil to overflow from the boom rodless chamber through the first boom oil circuit 23 to the oil replenishing circuit 6. The fourth overflow valve 33 is connected between the oil replenishing circuit 6 and the second boom oil circuit 24, and the fourth overflow valve 33 only allows oil to overflow from the boom rod chamber through the second boom oil circuit 24 to the oil replenishing circuit 6.

[0092] The second closed hydraulic system further includes a boom regeneration valve 34, which is configured to connect the first boom oil circuit 23 and the second boom oil circuit 24, or disconnect the first boom oil circuit 23 and the second boom oil circuit 24. Specifically, the connection between the boom regeneration valve 34 and the first boom oil circuit 23 is located between the boom control valve 29 and the second hydraulically controlled one-way valve 27. When the boom regeneration valve 34 is opened, the oil can flow directly between the boom rodless chamber and the boom rod chamber, and flow from the side with high pressure to the side with low pressure, so that the boom piston rod can move quickly.

[0093] Please refer to Figure 3 The bucket oil cylinder 3 includes a bucket rod chamber and a bucket rodless chamber with variable volumes. The bucket oil cylinder 3 also includes a bucket piston rod and a bucket cylinder body. The bucket piston rod divides the inner chamber of the bucket cylinder body into a bucket rod chamber and a bucket rodless chamber. The bucket piston rod passes through the bucket rod chamber so that the cross-sectional area of ​​the bucket rod chamber is smaller than the cross-sectional area of ​​the bucket rodless chamber. The bucket piston rod can move in the bucket cylinder body, and when the bucket piston rod moves, the volumes of the bucket rod chamber and the bucket rodless chamber increase and decrease. In this embodiment, the bucket cylinder body is hinged to the bucket rod, and the bucket piston rod is hinged to the bucket.

[0094] Optionally, the third closed hydraulic system includes a first bucket oil pump 35, a second bucket oil pump 39 and a bucket balancing valve 36, one end of the first bucket oil pump 35 is connected to the first bucket oil circuit 37, and the other end is connected to the second bucket oil circuit 38, the first bucket oil circuit 37 is connected to the bucket rodless chamber of the bucket cylinder 3, and the second bucket oil circuit 38 is connected to the bucket rod chamber of the bucket cylinder 3, the bucket balancing valve 36 is configured to connect the one with the smaller oil pressure between the first bucket oil circuit 37 and the second bucket oil circuit 38 to the oil replenishing circuit 6, one end of the second bucket oil pump 39 is connected to the oil replenishing circuit 6, and the other end of the second bucket oil pump 39 is connected to the third bucket oil circuit 40, and the third bucket oil circuit 40 is connected to the first bucket oil circuit 37. Since the cross-sectional areas of the bucket rod chamber and the bucket rodless chamber are different, there is a flow difference. When the first bucket oil pump 35 drives the oil to flow between the bucket rod chamber and the bucket rodless chamber, the second bucket oil pump 39 can drive the oil to flow between the oil replenishment circuit 6 and the bucket rodless chamber, and the bucket balance valve 36 connects the first bucket oil circuit 37 and the second bucket oil circuit 38 with the oil replenishment circuit 6, so as to balance the flow difference between the bucket rod chamber and the bucket rodless chamber. In addition, the oil temperature in the oil replenishment circuit 6 is relatively low, and the hot oil in the bucket hydraulic circuit can be replaced with the low-temperature oil in the oil replenishment circuit, so as to ensure the normal oil temperature in the bucket hydraulic circuit, and thus ensure the normal operation of the bucket cylinder 3. Among them, the first bucket oil pump 35 and the second bucket oil pump 39 are both closed pumps, and the first bucket oil pump 35 can rotate forward and reverse, and the second bucket oil pump 39 can also rotate forward and reverse. Specifically, both the first bucket oil pump 35 and the second bucket oil pump 39 may be fixed-measuring pumps.

[0095] When the bucket piston rod moves to the extended position, the bucket piston rod gradually extends outward, the first bucket oil pump 35 rotates forward, and pumps the oil in the bucket rod chamber to the bucket rodless chamber. If the bucket piston rod is subjected to a positive load at this time, the oil pressure in the bucket rod chamber is less than the oil pressure in the bucket rodless chamber, then the bucket balance valve 36 connects the second bucket oil circuit 38 and the oil replenishing circuit 6. If the bucket piston rod is subjected to a negative load at this time, the oil pressure in the bucket rod chamber is greater than the oil pressure in the bucket rodless chamber, then the bucket balance valve 36 connects the first bucket oil circuit 37 and the oil replenishing circuit 6. When the bucket piston rod moves to the retracted position, the bucket piston rod gradually retracts inward. If the bucket piston rod is subjected to a positive load at this time, and the oil pressure in the bucket rod chamber is greater than the oil pressure in the bucket rodless chamber, the bucket balance valve 36 connects the first bucket oil circuit 37 and the oil replenishing circuit 6. If the bucket piston rod is subjected to a negative load at this time, and the oil pressure in the bucket rod chamber is less than the oil pressure in the bucket rodless chamber, the bucket balance valve 36 connects the second bucket oil circuit 38 and the oil replenishing circuit 6.

[0096] In this embodiment, the bucket balancing valve 36 is a hydraulically controlled valve, and the bucket balancing valve 36 has a hydraulic control end A5 and a hydraulic control end A6. The hydraulic control end A5 is connected to the first bucket oil circuit 37, and the hydraulic control end A6 is connected to the second bucket oil circuit 38. The hydraulic control end A5 and the hydraulic control end A6 are respectively located on both sides of the valve core of the bucket balancing valve 36, and the oil of the hydraulic control end A5 and the hydraulic control end A6 directly acts on the valve core of the bucket balancing valve 36. The force of the oil of the hydraulic control end A5 acting on the valve core of the bucket balancing valve 36 and the force of the oil of the hydraulic control end A6 acting on the valve core of the bucket balancing valve 36 are compared to determine the stop position of the valve core of the bucket balancing valve 36. Among them, the bucket balancing valve 36 has a left position, a right position and a middle position. When the bucket balancing valve 36 is in the left position, the bucket balancing valve 36 connects the oil replenishing circuit 6 and the second bucket oil circuit 38; when the bucket balancing valve 36 is in the right position, the bucket balancing valve 36 connects the oil replenishing circuit 6 and the first bucket oil circuit 37; when the bucket balancing valve 36 is in the middle position, the first bucket oil circuit 37 and the second bucket oil circuit 38 are both disconnected from the oil replenishing circuit 6.

[0097] In this embodiment, the third closed hydraulic system also includes a fourth hydraulically controlled one-way valve 41 and a fifth hydraulically controlled one-way valve 42, wherein the fourth hydraulically controlled one-way valve 41 is arranged on the first bucket oil circuit 37. When the oil pressure of the oil delivered to the fourth hydraulically controlled one-way valve 41 exceeds the set value, the fourth hydraulically controlled one-way valve 41 can be opened, and the oil continues to be delivered to the bucket rodless chamber; when the oil pressure of the oil delivered to the fourth hydraulically controlled one-way valve 41 does not exceed the set value, the fourth hydraulically controlled one-way valve 41 disconnects the first bucket oil circuit 37. At this time, the fourth hydraulically controlled one-way valve 41 can be controlled to open or close by the hydraulically controlled valve group of the fourth hydraulically controlled one-way valve 41. The fifth hydraulically controlled one-way valve 42 is arranged on the second bucket oil circuit 38. When the oil pressure of the oil delivered to the fifth hydraulically controlled one-way valve 42 exceeds the set value, the fifth hydraulically controlled one-way valve 42 can be opened, and the oil continues to be delivered to the bucket rod chamber; when the oil pressure of the oil delivered to the fifth hydraulically controlled one-way valve 42 does not exceed the set value, the fifth hydraulically controlled one-way valve 42 disconnects the second bucket oil circuit 38. At this time, the fifth hydraulically controlled one-way valve 42 can be controlled to be opened or closed by the hydraulically controlled valve group of the fifth hydraulically controlled one-way valve 42. Among them, the specific structures of the fourth hydraulically controlled one-way valve 41 and the fifth hydraulically controlled one-way valve 42 are prior arts and are not described in detail here.

[0098] The third closed hydraulic system also includes a bucket control valve 43 , which is disposed in the first bucket oil circuit 37 and located between the connection between the third bucket oil circuit 40 and the first bucket oil circuit 37 and the first bucket oil pump 35 . The bucket control valve 43 is used to open or close the first bucket oil circuit 37 .

[0099] The third closed hydraulic system further includes a fifth oil replenishment check valve 44 and a sixth oil replenishment check valve 45. The fifth oil replenishment check valve 44 is connected between the oil replenishment oil circuit 6 and the first bucket oil circuit 37, and the fifth oil replenishment check valve 44 only allows oil to flow from the oil replenishment oil circuit 6 to the first bucket oil circuit 37. The sixth oil replenishment check valve 45 only allows oil to flow from the oil replenishment oil circuit 6 to the second bucket oil circuit 38.

[0100] The third closed hydraulic system also includes a fifth overflow valve 46 and a sixth overflow valve 47. The fifth overflow valve 46 is connected between the oil replenishing circuit 6 and the first bucket oil circuit 37, and the fifth overflow valve 46 only allows oil to overflow from the bucket rodless chamber through the first bucket oil circuit 37 to the oil replenishing circuit 6. The sixth overflow valve 47 is connected between the oil replenishing circuit 6 and the second bucket oil circuit 38, and the sixth overflow valve 47 only allows oil to overflow from the bucket rod chamber through the second bucket oil circuit 38 to the oil replenishing circuit 6.

[0101] The third closed hydraulic system further includes a bucket regeneration valve 48, which is configured to connect the first bucket oil circuit 37 and the second bucket oil circuit 38, or disconnect the first bucket oil circuit 37 and the second bucket oil circuit 38. Specifically, the connection between the bucket regeneration valve 48 and the first bucket oil circuit 37 is located between the bucket control valve 43 and the fourth hydraulically controlled one-way valve 41. When the bucket regeneration valve 48 is opened, the oil can flow directly between the bucket rodless chamber and the bucket rod chamber, and flow from the side with high pressure to the side with low pressure, so that the bucket piston rod can move quickly.

[0102] Among them, the first boom oil pump 8 and the second boom oil pump 12 can both be driven by a motor or an internal combustion engine; the first boom oil pump 21 and the second boom oil pump 25 can both be driven by a motor or an internal combustion engine; the first bucket oil pump 35 and the second bucket oil pump 39 can both be driven by a motor or an internal combustion engine.

[0103] Please refer to Figure 4 The oil replenishment control method of the hydraulic system of the excavator includes the following steps:

[0104] S100: Obtain the required flow of the boom cylinder, the required flow of the arm cylinder, and the required flow of the bucket cylinder.

[0105] Specifically, obtaining the flow demand of the boom cylinder may include:

[0106] S1011: Obtain the flow rate of oil flowing through the second boom oil pump and the flow rate of oil flowing through the boom balance valve.

[0107] S1012: Determine the required flow rate of the boom cylinder based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve.

[0108] The flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve can be detected by a flow sensor.

[0109] Among them, taking the extension of the boom piston rod as an example, when the boom piston rod is extended, under the drive of the first boom oil pump, the oil in the boom rod chamber is pumped into the boom rodless chamber. If the boom piston rod is subjected to a positive load at this time, the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber, and the boom balance valve connects the second boom oil circuit and the oil replenishment circuit. Since the cross-sectional area of ​​the boom rod chamber is smaller than the cross-sectional area of ​​the boom rodless chamber, the flow rate of the oil that needs to enter the boom rodless chamber needs to be greater than the flow rate of the oil discharged from the boom rod chamber, and the oil in the oil replenishment circuit enters the second boom oil circuit through the boom balance valve; at the same time, the second boom oil pump drives the oil from the oil replenishment circuit to enter the boom rodless chamber through the third boom oil circuit. Therefore, the sum of the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve is the required flow rate of the boom cylinder at this time, and the required flow rate of the boom cylinder is a positive value.

[0110] If the boom piston rod is subjected to negative load at this time, and the oil pressure in the boom rod chamber is greater than the oil pressure in the boom rodless chamber, the boom balance valve connects the first boom oil circuit and the oil replenishment circuit. At this time, under the action of the oil pressure difference between the boom rod chamber and the boom rodless chamber, the oil can flow from the boom rod chamber through the first boom oil pump to the boom rodless chamber, and the oil drives the first boom oil pump to rotate. If the first boom oil pump is driven by a motor, the first boom oil pump can also drive the motor to generate electricity, and the boom balancing valve connects the first boom oil circuit and the oil replenishing circuit, and the oil in the oil replenishing circuit enters the boom rodless chamber through the boom balancing valve to make up for the flow difference between the boom rod chamber and the boom rodless chamber; at the same time, the second boom oil pump does not work, that is, the amount of oil flowing through the second boom oil pump is zero. At this time, the sum of the oil flow rate flowing through the second boom oil pump and the oil flow rate flowing through the boom balancing valve is also the required flow rate of the boom cylinder at this time, and the required flow rate of the boom cylinder is a positive value.

[0111] Similarly, when the boom piston rod retracts, the sum of the oil flow rate flowing through the second boom oil pump and the oil flow rate flowing through the boom balance valve is also the required flow rate of the boom cylinder at this time, but when the boom piston rod retracts, the required flow rate of the boom cylinder is a negative value.

[0112] As an alternative solution, obtaining the flow demand of the boom cylinder may also include:

[0113] S1021: Obtain the position of the joystick.

[0114] The operating handle is used to control the moving direction and moving speed of the boom piston rod, and is a prior art, which will not be described in detail herein. The position of the operating handle can be detected by a position sensor arranged on the operating handle.

[0115] S1022: Determine the movement direction and movement speed of the boom piston rod of the boom cylinder based on the position of the operating handle.

[0116] A first mapping relationship between the position of the operating handle and the movement direction of the boom piston rod is pre-stored in the memory. The movement direction of the boom piston rod can be determined based on the position of the operating handle and the first mapping relationship, wherein the movement direction of the boom piston rod includes an extension direction and a retraction direction. The first mapping relationship can be obtained through a large number of preliminary experiments.

[0117] The memory pre-selects and stores a second mapping relationship between the position of the joystick and the movement speed of the boom piston rod, and the movement speed of the boom piston rod can be determined according to the position of the joystick and the second mapping relationship. The second mapping relationship can be obtained through a large number of experiments in the early stage.

[0118] S1023: Obtain the area of ​​the boom rod chamber of the boom cylinder and the area of ​​the boom rodless chamber of the boom cylinder.

[0119] The area of ​​the boom rod chamber of the boom cylinder and the area of ​​the boom rodless chamber of the boom cylinder are both related to the specific model of the boom cylinder and can be pre-stored in the memory.

[0120] S1024: Determine the required flow rate of the boom cylinder based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity, and the area of ​​the boom rodless cavity.

[0121] A map1 is pre-selected and stored in the memory, which includes the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod chamber, the area of ​​the boom rodless chamber and the required flow of the boom cylinder. The required flow of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod chamber, the area of ​​the boom rodless chamber and map1.

[0122] Among them, the movement speed of the boom piston rod is V1, the movement direction of the boom piston rod is the extension direction, and the area of ​​the boom rod cavity is A 11 , the area of ​​the boom rodless cavity is A 12 , the required flow of the boom cylinder is Q1, then the relationship model corresponding to map1 is: Q1=V1*A 11 -V1*A 12 .

[0123] Obtaining the flow requirements of the boom cylinder may include:

[0124] S1031: Obtaining the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve;

[0125] S1032: Determine the required flow rate of the boom cylinder based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve.

[0126] The flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve can be detected by a flow sensor.

[0127] Among them, taking the extension of the boom piston rod as an example, when the boom piston rod is extended, under the drive of the first boom oil pump, the oil in the boom rod chamber is pumped into the boom rodless chamber. If the boom piston rod is subjected to a positive load at this time, the oil pressure in the boom rod chamber is less than the oil pressure in the boom rodless chamber. The boom balance valve connects the second boom oil circuit and the oil replenishment circuit. Since the cross-sectional area of ​​the boom rod chamber is smaller than the cross-sectional area of ​​the boom rodless chamber, the flow rate of the oil that needs to enter the boom rodless chamber needs to be greater than the flow rate of the oil discharged from the boom rod chamber. The oil in the oil replenishment circuit enters the second boom oil circuit through the boom balance valve; at the same time, the second boom oil pump drives the oil from the oil replenishment circuit to enter the boom rodless chamber through the third boom oil circuit. Therefore, the sum of the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve is the required flow rate of the boom cylinder at this time, and the required flow rate of the boom cylinder is a positive value.

[0128] If the boom piston rod is under negative load at this time, and the oil pressure in the boom cavity is greater than the oil pressure in the boom cavity, the boom balance valve connects the first boom oil circuit and the oil replenishment circuit. At this time, under the action of the oil pressure difference between the boom rod chamber and the boom rodless chamber, the oil can flow from the boom rod chamber through the first boom oil pump to the boom rodless chamber, and the oil drives the first boom oil pump to rotate. If the first boom oil pump is driven by a motor, the first boom oil pump can also drive the motor to generate electricity, and the boom balance valve connects the first boom oil circuit and the oil replenishment circuit, and the oil in the oil replenishment circuit enters the boom rodless chamber through the boom balance valve to make up for the flow difference between the boom rod chamber and the boom rodless chamber; at the same time, the second boom oil pump does not work, that is, the amount of oil flowing through the second boom oil pump is zero. At this time, the sum of the oil flow rate flowing through the second boom oil pump and the oil flow rate flowing through the boom balance valve is also the required flow rate of the boom cylinder at this time, and the required flow rate of the boom cylinder is a positive value.

[0129] Similarly, when the boom piston rod retracts, the sum of the oil flow rate flowing through the second boom oil pump and the oil flow rate flowing through the boom balancing valve is also the required flow rate of the boom cylinder at this time, but when the boom piston rod retracts, the required flow rate of the boom cylinder is a negative value.

[0130] Obtaining the flow requirements of the boom cylinder can also include:

[0131] S1041: Obtain the position of the joystick.

[0132] The joystick is used to control the movement direction and movement speed of the piston rod of the bucket rod, and is a prior art, which will not be described in detail here. The position of the joystick can be detected by a position sensor arranged on the joystick.

[0133] S1042: Determine the movement direction of the boom piston rod of the boom cylinder and the movement speed of the boom piston rod of the boom cylinder based on the position of the control handle.

[0134] The memory pre-stores a third mapping relationship between the position of the operating handle and the movement direction of the boom piston rod. The movement direction of the boom piston rod can be determined based on the position of the operating handle and the third mapping relationship, wherein the movement direction of the boom piston rod includes an extension direction and a retraction direction. The third mapping relationship can be obtained through a large number of preliminary experiments.

[0135] The memory pre-selects and stores a fourth mapping relationship between the position of the joystick and the movement speed of the boom piston rod, and the movement speed of the boom piston rod can be determined according to the position of the joystick and the fourth mapping relationship. The fourth mapping relationship can be obtained through a large number of experiments in the early stage.

[0136] S1043: Obtain the area of ​​the arm cavity with a rod and the area of ​​the arm cavity without a rod of the arm cylinder.

[0137] The area of ​​the rod cavity of the boom cylinder and the area of ​​the rodless cavity of the boom cylinder are both related to the specific model of the boom cylinder and can be pre-stored in the memory.

[0138] S1044: Determine the required flow rate of the boom cylinder based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity, and the area of ​​the boom rodless cavity.

[0139] The memory pre-stores map2 of the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity, the area of ​​the boom rodless cavity and the required flow of the boom cylinder. The required flow of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity, the area of ​​the boom rodless cavity and map2.

[0140] Among them, the movement speed of the bucket rod piston rod is V2, the movement direction of the bucket rod piston rod is the extension direction, and the area of ​​the bucket rod cavity is A 21 The area of ​​the arm cavity without rod is A 22 , the required flow of the boom cylinder is Q2, then the relationship model corresponding to map2 is: Q2=V2*A 21 -V2*A 22 .

[0141] Obtaining the flow requirements of the bucket cylinder may include:

[0142] S1051: Obtain the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve.

[0143] S1052: Determine the required flow rate of the bucket cylinder based on the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve.

[0144] The flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve can be detected by a flow sensor.

[0145] Among them, taking the extension of the bucket piston rod as an example, when the bucket piston rod is extended, under the drive of the first bucket oil pump, the oil in the bucket rod chamber is pumped into the bucket rodless chamber. If the bucket piston rod is subjected to a positive load at this time, the oil pressure in the bucket rod chamber is less than the oil pressure in the bucket rodless chamber, and the bucket balance valve connects the second bucket oil circuit and the oil replenishment circuit. Since the cross-sectional area of ​​the bucket rod chamber is smaller than the cross-sectional area of ​​the bucket rodless chamber, the flow rate of the oil that needs to enter the bucket rodless chamber must be greater than the flow rate of the oil discharged from the bucket rod chamber, and the oil in the oil replenishment circuit enters the second bucket oil circuit through the bucket balance valve; at the same time, the second bucket oil pump drives the oil from the oil replenishment circuit through the third bucket oil circuit into the bucket rodless chamber. Therefore, the sum of the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve is the required flow rate of the bucket cylinder at this time, and the required flow rate of the bucket cylinder is a positive value.

[0146] If the bucket piston rod is subjected to negative load at this time, and the oil pressure in the bucket rod chamber is greater than the oil pressure in the bucket rodless chamber, the bucket balance valve connects the first bucket oil circuit and the oil replenishment circuit. At this time, under the action of the oil pressure difference between the bucket rod chamber and the bucket rodless chamber, the oil can flow from the bucket rod chamber through the first bucket oil pump to the bucket rodless chamber, and the oil drives the first bucket oil pump to rotate. If the first bucket oil pump is driven by a motor, the first bucket oil pump can also drive the motor to generate electricity, and the bucket balance valve connects the first bucket oil circuit and the oil replenishment circuit, and the oil in the oil replenishment circuit enters the bucket rodless chamber through the bucket balance valve to make up for the flow difference between the bucket rod chamber and the bucket rodless chamber; at the same time, the second bucket oil pump does not work, that is, the amount of oil flowing through the second bucket oil pump is zero, and at this time, the sum of the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve is also the required flow rate of the bucket cylinder at this time, and the required flow rate of the bucket cylinder is a positive value.

[0147] Similarly, when the bucket piston rod retracts, the sum of the oil flow rate flowing through the second bucket oil pump and the oil flow rate flowing through the bucket balance valve is also the required flow rate of the bucket cylinder at this time, but when the bucket piston rod retracts, the required flow rate of the bucket cylinder is a negative value.

[0148] Obtaining the flow requirements of the bucket cylinder may also include:

[0149] S1061: Obtain the position of the joystick.

[0150] The joystick is used to control the movement direction and movement speed of the bucket piston rod, and is a prior art, which will not be described in detail here. The position of the joystick can be detected by a position sensor arranged on the joystick.

[0151] S1062: Determine a movement direction and a movement speed of a bucket piston rod of a bucket cylinder based on the position of the operating handle.

[0152] The memory pre-selects and stores a fifth mapping relationship between the position of the operating handle and the movement direction of the bucket piston rod. The movement direction of the bucket piston rod can be determined based on the position of the operating handle and the fifth mapping relationship, wherein the movement direction of the bucket piston rod includes an extension direction and a retraction direction. The fifth mapping relationship can be obtained through a large number of preliminary experiments.

[0153] The memory pre-selects and stores a sixth mapping relationship between the position of the joystick and the movement speed of the bucket piston rod, and the movement speed of the bucket piston rod can be determined according to the position of the joystick and the sixth mapping relationship. The sixth mapping relationship can be obtained through a large number of experiments in the early stage.

[0154] S1063: Obtain the area of ​​the bucket rod cavity of the bucket cylinder and the area of ​​the bucket rodless cavity of the bucket cylinder.

[0155] The area of ​​the bucket rod cavity of the bucket cylinder and the area of ​​the bucket rodless cavity of the bucket cylinder are both related to the specific model of the bucket cylinder and can be pre-stored in the memory.

[0156] S1064: Determine the required flow rate of the bucket cylinder based on the movement direction of the bucket piston rod, the movement speed of the bucket piston rod, the area of ​​the bucket rod cavity, and the area of ​​the bucket rodless cavity.

[0157] The memory pre-stores map3 of the movement direction of the bucket piston rod, the movement speed of the bucket piston rod, the area of ​​the bucket rod cavity, the area of ​​the bucket rodless cavity and the required flow of the bucket cylinder. The required flow of the bucket cylinder is determined according to the movement direction of the bucket piston rod, the movement speed of the bucket piston rod, the area of ​​the bucket rod cavity, the area of ​​the bucket rodless cavity and map3.

[0158] Among them, the movement speed of the bucket piston rod is V3, the movement direction of the bucket piston rod is the extension direction, and the area of ​​the bucket rod cavity is A 31 The area of ​​the bucket without rod cavity is A 32 , the required flow of the bucket cylinder is Q3, then the relationship model corresponding to map3 is: Q3=V3*A 31 -V3*A 32 .

[0159] S200: Determine a required rotation speed of the oil replenishment pump based on a required flow rate of the boom cylinder, a required flow rate of the arm cylinder, and a required flow rate of the bucket cylinder.

[0160] The memory stores in advance the correspondence between the required flow of the boom cylinder, the required flow of the stick cylinder, the required flow of the bucket cylinder and the required speed of the oil replenishment pump, and the required speed of the oil replenishment pump can be determined based on the obtained required flow of the boom cylinder, the required flow of the stick cylinder and the required flow of the bucket cylinder, and the correspondence. The correspondence can be obtained through a large number of experiments in the early stage.

[0161] S300: The charge pump runs at the required speed.

[0162] When the oil replenishment pump runs at the required speed, the flow rate of the oil replenished by the oil replenishment pump can match the total flow rate required by the boom cylinder, bucket cylinder and stick cylinder, avoiding the oil replenishment pump speed being too high, causing a large amount of oil overflow in the oil replenishment circuit and resulting in energy waste.

[0163] S400: Obtain the current pressure of the oil replenishment circuit.

[0164] The current pressure of the charge oil circuit can be detected by the pressure sensor.

[0165] S500: Calculate the difference between the set pressure and the current pressure.

[0166] The set pressure can be set according to actual needs and stored in the memory in advance.

[0167] S600: Determine the difference between the difference value and the set value.

[0168] If the difference is greater than the set value, S700 is executed; if the difference is not greater than the set value, the process returns to S100 and the speed of the charge pump is kept unchanged.

[0169] S700: Increase the speed of the charge pump by the set speed based on the current speed.

[0170] After executing S700, return to step S400.

[0171] The size of the set speed can be set according to actual needs. When the difference is not greater than the set value, the oil replenishment circuit can maintain a stable oil replenishment effect when replenishing the oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system; when the difference is greater than the set value, it will affect the stability of the oil replenishment circuit when replenishing the oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system, so the speed of the oil replenishment pump is increased. In addition, the oil pressure of the overflow valve is not less than the set oil pressure.

[0172] The oil replenishment control method of the excavator hydraulic system provided in the present embodiment obtains the required flow of the boom cylinder, the required flow of the arm cylinder and the bucket cylinder, and determines the required speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the arm cylinder and the bucket cylinder; the oil replenishment pump runs at the required speed; obtains the current pressure of the oil replenishment circuit; calculates the difference between the set pressure and the current pressure; judges the size of the difference and the set value; when the difference is greater than the set value: increases the speed of the oil replenishment pump by the set speed on the current basis and returns to the step of obtaining the current pressure of the oil replenishment circuit, so that the speed of the oil replenishment pump can match the total flow required by the boom cylinder, the bucket cylinder and the arm cylinder, avoids the oil replenishment pump speed being too high, resulting in energy waste, and the speed of the oil replenishment pump can also ensure that the oil pressure of the oil replenishment circuit stably replenishes oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system.

[0173] Embodiment 2

[0174] This embodiment provides an oil replenishment control device for an excavator hydraulic system, which is used to implement the oil replenishment control method for an excavator hydraulic system in Embodiment 1, and has corresponding functional modules and beneficial effects for executing the method.

[0175] Please refer to Figure 5 The oil replenishment control device of the hydraulic system of the excavator includes a flow acquisition module 50, a required speed determination module 51, an execution module 52, a current pressure acquisition module 53, a difference calculation module 54, a judgment module 55 and a speed increase module 56. Among them, the flow acquisition module 50 is used to obtain the required flow of the boom cylinder, the required flow of the dipper cylinder and the required flow of the bucket cylinder; the required speed determination module 51 is used to determine the required speed of the replenishment pump based on the required flow of the boom cylinder, the required flow of the dipper cylinder and the required flow of the bucket cylinder; the execution module 52 is used to make the replenishment pump run at the required speed; the current pressure acquisition module 53 is used to obtain the current pressure of the replenishment oil circuit; the difference calculation module 54 is used to calculate the difference between the set pressure and the current pressure; the judgment module 55 is used to judge the size of the difference and the set value; when the difference is greater than the set value, the speed increase module 56 is used to increase the speed of the replenishment pump to the set speed based on the current speed.

[0176] Embodiment 3

[0177] Figure 6It is a structural schematic diagram of a control system of an excavator hydraulic system provided by an embodiment of the present invention. Excavator (or terminal device) is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The terminal device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are only examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0178] like Figure 6 As shown, the terminal device 100 includes one or more processors 110, and a storage device, which is communicatively connected to the processor 110, such as a ROM 120, a random access RAM 130, etc., wherein the storage device stores a computer program that can be executed by one or more processors, and the processor 110 can perform various appropriate actions and processes according to the computer program stored in the ROM 120 or the computer program loaded from the storage unit 180 to the random access RAM 130. In the RAM 130, various programs and data required for the operation of the terminal device 100 can also be stored. The processor 110, the ROM 120, and the RAM 130 are connected to each other via a bus 140. The I / O interface 150 is also connected to the bus 140.

[0179] A number of components in the terminal device 100 are connected to the I / O interface 150, including: an input unit 160, such as a keyboard, a mouse, etc.; an output unit 170, such as various types of displays, speakers, etc.; a storage unit 180, such as a disk, an optical disk, etc.; and a communication unit 190, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 190 allows the terminal device 100 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0180] The processor 110 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 110 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 110 executes the various methods and processes described above, such as the oil replenishment control method of the hydraulic system of the excavator.

[0181] In some embodiments, the oil replenishment control method of the excavator hydraulic system may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 180. In some embodiments, part or all of the computer program may be loaded and / or installed on the terminal device 100 via the ROM 120 and / or the communication unit 190. When the computer program is loaded into the RAM 130 and executed by the processor 110, one or more steps of the oil replenishment control method of the excavator hydraulic system described above may be executed. Alternatively, in other embodiments, the processor 110 may be configured to execute the oil replenishment control method of the excavator hydraulic system in any other appropriate manner (e.g., by means of firmware).

[0182] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0183] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0184] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device, or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0185] To provide interaction with a user, the systems and techniques described herein may be implemented on a terminal device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the terminal device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0186] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0187] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0188] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0189] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An oil replenishment control method for an excavator hydraulic system, characterized in that: The hydraulic system of the excavator includes a first closed hydraulic system, a second closed hydraulic system, a third closed hydraulic system and an oil replenishment pump, wherein the first closed hydraulic system is used to drive the boom cylinder to move, the second closed hydraulic system is used to drive the dipper cylinder to move, and the third closed hydraulic system is used to drive the bucket cylinder to move, and the two ends of the oil replenishment pump are respectively connected to the oil tank and the oil replenishment oil circuit, and the oil replenishment oil circuit is used to supply oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system; the oil replenishment control method of the hydraulic system of the excavator includes: Obtain the required flow of the boom cylinder, the arm cylinder and the bucket cylinder; Determining a required rotation speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the arm cylinder, and the required flow of the bucket cylinder; The oil charge pump operates at a required speed; Get the current pressure of the oil replenishment circuit; Calculating the difference between the set pressure and the current pressure; Determine the difference between the value and the set value; If the difference is greater than the set value, the speed of the oil replenishment pump is increased to the set speed based on the current speed and the process returns to the step of obtaining the current pressure of the oil replenishment circuit.

2. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The first closed hydraulic system comprises a first boom oil pump, a second boom oil pump and a boom balancing valve, one end of the first boom oil pump is connected to the first boom oil circuit, and the other end is connected to the second boom oil circuit, the first boom oil circuit is connected to the boom rodless chamber of the boom oil cylinder, the second boom oil circuit is connected to the boom rod chamber of the boom oil cylinder, the boom balancing valve is configured to connect the one with the smaller oil pressure of the first boom oil circuit and the second boom oil circuit to the oil replenishment circuit, one end of the second boom oil pump is connected to the oil replenishment circuit, the other end of the second boom oil pump is connected to the third boom oil circuit, and the third boom oil circuit is connected to the first boom oil circuit; Obtaining the required flow of the boom cylinder includes: Obtaining the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve; The required flow rate of the boom cylinder is determined based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balance valve.

3. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The excavator includes a joystick, which is used to control the extension and retraction of the boom piston rod of the boom cylinder; Obtaining the required flow of the boom cylinder includes: Obtaining the position of the joystick; Determining the movement direction of the boom piston rod and the movement speed of the boom piston rod based on the position of the operating handle; Obtain the area of ​​the boom rod chamber of the boom cylinder and the area of ​​the boom rodless chamber of the boom cylinder; The required flow rate of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod chamber and the area of ​​the boom rodless chamber.

4. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The second closed hydraulic system comprises a first boom oil pump, a second boom oil pump and a boom balancing valve, one end of the first boom oil pump is connected to the first boom oil circuit, and the other end is connected to the second boom oil circuit, the first boom oil circuit is connected to the boom rodless chamber of the boom cylinder, the second boom oil circuit is connected to the boom rod chamber of the boom cylinder, the boom balancing valve is configured to connect the one with the smaller oil pressure of the first boom oil circuit and the second boom oil circuit to the oil replenishment circuit, one end of the second boom oil pump is connected to the oil replenishment circuit, the other end of the second boom oil pump is connected to the third boom oil circuit, and the third boom oil circuit is connected to the first boom oil circuit; Obtaining the required flow of the boom cylinder includes: Obtaining the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve; The required flow rate of the boom cylinder is determined based on the flow rate of the oil flowing through the second boom oil pump and the flow rate of the oil flowing through the boom balancing valve.

5. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The excavator includes a joystick, which is used to control the extension and retraction of the boom piston rod of the boom cylinder; Obtaining the required flow of the boom cylinder includes: Obtaining the position of the joystick; Determining the direction of movement of the boom piston rod and the speed of movement of the boom piston rod based on the position of the control handle; Obtaining the area of ​​the arm cavity of the arm cylinder and the area of ​​the rodless cavity of the arm of the arm cylinder; The required flow of the boom cylinder is determined based on the movement direction of the boom piston rod, the movement speed of the boom piston rod, the area of ​​the boom rod cavity and the area of ​​the boom rodless cavity.

6. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The third closed hydraulic system includes a first bucket oil pump, a second bucket oil pump and a bucket balancing valve, one end of the first bucket oil pump is connected to the first bucket oil circuit, and the other end is connected to the second bucket oil circuit, the first bucket oil circuit is connected to the bucket rodless chamber of the bucket cylinder, and the second bucket oil circuit is connected to the bucket rod chamber of the bucket cylinder, the bucket balancing valve is configured to connect the one with the smaller oil pressure of the first bucket oil circuit and the second bucket oil circuit to the oil replenishment oil circuit, one end of the second bucket oil pump is connected to the oil replenishment oil circuit, and the other end of the second bucket oil pump is connected to the third bucket oil circuit, and the third bucket oil circuit is connected to the first bucket oil circuit; Obtaining the required flow of the bucket cylinder includes: Obtaining the flow rate of the oil flowing through the second bucket oil pump and the flow rate of the oil flowing through the bucket balance valve; A required flow rate of the bucket cylinder is determined based on a flow rate of the oil flowing through the second bucket oil pump and a flow rate of the oil flowing through the bucket balance valve.

7. The oil replenishment control method of the hydraulic system of an excavator according to claim 1, characterized in that: The excavator includes a joystick, which is used to control the extension and retraction of the bucket piston rod of the bucket cylinder; Obtaining the required flow of the bucket cylinder includes: Obtaining the position of the joystick; Determining the movement direction of the bucket piston rod and the movement speed of the bucket piston rod based on the position of the joystick; Obtain the area of ​​the bucket rod cavity of the bucket cylinder and the area of ​​the bucket rodless cavity of the bucket cylinder; The required flow rate of the bucket cylinder is determined based on the movement direction of the bucket piston rod, the movement speed of the bucket piston rod, the area of ​​the bucket rod cavity and the area of ​​the bucket rodless cavity.

8. An oil replenishment control device for an excavator hydraulic system, characterized in that: The hydraulic system of the excavator includes a first closed hydraulic system, a second closed hydraulic system, a third closed hydraulic system and an oil replenishment pump, wherein the first closed hydraulic system is used to drive the boom cylinder to move, the second closed hydraulic system is used to drive the dipper cylinder to move, and the third closed hydraulic system is used to drive the bucket cylinder to move, and the two ends of the oil replenishment pump are respectively connected to the oil tank and the oil replenishment oil circuit, and the oil replenishment oil circuit is used to supply oil to the first closed hydraulic system, the second closed hydraulic system and the third closed hydraulic system; the oil replenishment control device of the hydraulic system of the excavator includes: A flow acquisition module is used to acquire the required flow of the boom cylinder, the required flow of the arm cylinder and the required flow of the bucket cylinder; A required speed determination module, used to determine the required speed of the oil replenishment pump based on the required flow of the boom cylinder, the required flow of the dipper cylinder and the required flow of the bucket cylinder; An execution module, used for making the oil charge pump run at a required speed; A current pressure acquisition module is used to obtain the current pressure of the oil replenishment circuit; A difference calculation module, used for calculating the difference between the set pressure and the current pressure; A judgment module is used to judge the difference between the difference value and the set value; The speed increasing module is used to increase the speed of the oil replenishment pump by a set speed based on the current speed when the difference is greater than a set value.

9. An excavator, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors control the excavator to implement the oil replenishment control method of the excavator hydraulic system according to any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the excavator implements the oil replenishment control method of the excavator hydraulic system according to any one of claims 1 to 7.

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