Hydraulic system of excavator and excavator

Abstract

The application discloses a hydraulic system of an excavator and the excavator. The hydraulic system comprises first and second oil pumps, a superstructure and undercarriage control assembly, a common oil supply circuit and an oil regulating valve group. The undercarriage control assembly comprises left and right travelling devices. The oil regulating valve group comprises first to third left oil regulating ports, first and second right oil regulating ports and left and right oil regulating inlet ports connected with the first and second oil pumps respectively. The first and third left oil regulating ports are connected with the left travelling device. The second left oil regulating port and the second right oil regulating port are connected with the common oil supply circuit. The first right oil regulating port is connected with the right travelling device. The left oil regulating inlet port is communicated with the second left oil regulating port. The right oil regulating inlet port is communicated with the first right oil regulating port. In a first working state, the left oil regulating inlet port is communicated with the first left oil regulating port, and the right oil regulating inlet port is communicated with the second right oil regulating port. In a second working state, the left oil regulating inlet port is communicated with the second right oil regulating port, and the right oil regulating inlet port is communicated with the third left oil regulating port. The overall coordination is improved.

Description

Technical Field

[0001] This application relates to the field of excavator technology, and particularly to a hydraulic system for an excavator and an excavator. Background Technology

[0002] Hydraulic excavators are widely used in various engineering construction applications, but their high fuel consumption and operating costs make overall machine efficiency and fuel consumption the most critical indicators for evaluating their performance.

[0003] Traditional excavator hydraulic systems typically use integrated multi-way valves to control the operation of different hydraulic actuators. However, this design has a significant drawback: low coordination between the upper and lower sections. This means that in some working scenarios, the excavator may not be able to meet demanding operational requirements, limiting its work efficiency. Furthermore, existing excavators with integrated multi-way valves suffer from pressure loss due to the long and numerous oil supply lines between the integrated multi-way valve and each working cylinder, coupled with limitations in pipe diameter and high line losses. This reduces energy utilization.

[0004] It should be noted that the statements in this background section only provide background information relevant to this application and do not necessarily constitute prior art. Summary of the Invention

[0005] This application provides a hydraulic system for an excavator and the excavator itself to improve overall coordination.

[0006] The first aspect of this application provides a hydraulic system for an excavator, comprising:

[0007] tank;

[0008] A pump assembly, fluidly connected to an oil tank, includes a first oil pump and a second oil pump arranged in parallel.

[0009] The loading control component is used to connect with the loading working mechanism and drive the loading working mechanism to move;

[0010] The disembarkation control assembly includes a left-side travel mechanism and a right-side travel mechanism;

[0011] A common oil supply line, fluidly connected to the upper vehicle control components, is used to supply oil to the upper vehicle control components; and

[0012] The oil regulating valve assembly includes a left oil inlet, a first left regulating port, a second left regulating port, a third left regulating port, a right oil inlet, a first right regulating port, and a second right regulating port. The left oil inlet is fluidly connected to a first oil pump. The right oil inlet is fluidly connected to a second oil pump. Both the first and third left regulating ports are fluidly connected to a left-side travel device. The second left regulating port is fluidly connected to the common oil supply circuit. The first right regulating port is fluidly connected to the right-side travel device. The second right regulating port is fluidly connected to the common oil supply circuit. The left oil inlet is connected to the second left regulating port. The right oil inlet is connected to the first right regulating port. The oil regulating valve assembly has a first operating state and a second operating state. In the first operating state, the left oil inlet is configured to also be connected to the first left oil inlet, and the right oil inlet is configured to also be connected to the second right oil inlet. The first oil pump supplies oil to the common oil supply circuit and the left travel device, and the second oil pump supplies oil to the common oil supply circuit and the right travel device. In the second operating state, the left oil inlet is configured to also be connected to the second right oil inlet, and the right oil inlet is configured to also be connected to the third left oil inlet. The first oil pump supplies oil to the common oil supply circuit, and the second oil pump supplies oil to the left travel device and the right travel device.

[0013] In some embodiments, the left and right oil inlets of the oil regulating valve assembly are connected on and off. In a second operating state, when there is a pressure difference between the common oil supply circuit and the left travel device and / or the right travel device, the left and right oil inlets of the oil regulating valve are connected to allow mutual oil replenishment between the common oil supply circuit and the alighting control assembly.

[0014] In some embodiments, the oil regulating valve assembly includes a first control valve assembly and a second control valve assembly. The first control valve assembly includes a first oil outlet and a second oil outlet. The oil inlet of the first control valve assembly is fluidly connected to the left oil regulating inlet. The first oil outlet is fluidly connected to the first left oil regulating inlet. The second oil outlet is fluidly connected to the second right oil regulating inlet. The second control valve assembly includes a third oil outlet and a fourth oil outlet. The oil inlet of the second control valve assembly is fluidly connected to the right oil regulating inlet. The third oil outlet is fluidly connected to the third left oil regulating inlet. The fourth oil outlet is fluidly connected to the second right oil regulating inlet. In a first operating state, the oil inlet of the first control valve assembly is connected to the first oil outlet, and the oil inlet of the second control valve assembly is connected to the fourth oil outlet. In a second operating state, the oil inlet of the first control valve assembly is connected to the second oil outlet, and the oil inlet of the second control valve assembly is connected to the third oil outlet.

[0015] In some embodiments, the first control valve group includes a first on-off valve and a second on-off valve. The second control valve group includes a third on-off valve and a fourth on-off valve. The inlet of the first on-off valve is fluidly connected to the left oil inlet of the regulating valve, the inlet of the second on-off valve, and the second left regulating valve. The outlet of the first on-off valve is fluidly connected to the first left regulating valve. The outlet of the second on-off valve is fluidly connected to the second right regulating valve. The inlet of the third on-off valve is fluidly connected to the right oil inlet of the regulating valve, the inlet of the fourth on-off valve, and the first right regulating valve. The outlet of the fourth on-off valve is fluidly connected to the second right regulating valve. In a first operating state, the internal oil passages of the first and fourth on-off valves are connected, while the internal oil passages of the second and third on-off valves are disconnected. In a second operating state, the internal oil passages of the second and third on-off valves are connected, while the internal oil passages of the first and fourth on-off valves are disconnected.

[0016] In some embodiments, the oil regulating valve assembly further includes a replenishing oil circuit and a replenishing oil on / off valve. The replenishing oil circuit is disposed between the oil outlet of the second on / off valve and the oil outlet of the third on / off valve. The replenishing oil on / off valve is disposed on the replenishing oil circuit. In the second operating state, when there is a pressure difference between the common oil supply circuit and the left travel device and / or the right travel device, the replenishing oil on / off valve is connected to allow mutual oil replenishment between the common oil supply circuit and the alighting control component.

[0017] In some embodiments, the upper vehicle control assembly includes a plurality of upper vehicle control valve assemblies. The upper vehicle working mechanism includes a plurality of working cylinders, each fluidly connected to one of the plurality of upper vehicle control valve assemblies. Oil output from the pump assembly flows to the plurality of upper vehicle control valve assemblies via an oil regulating valve assembly and a common oil supply circuit to drive the plurality of working cylinders. The excavator's hydraulic system also includes a regeneration common oil circuit. The plurality of upper vehicle control valve assemblies are fluidly connected via the regeneration common oil circuit so that when a pressure difference exists between the plurality of working cylinders, the plurality of working cylinders replenish each other with oil via the regeneration common oil circuit.

[0018] In some embodiments, the plurality of upper structure control valve assemblies include a boom control valve assembly and a stick control valve assembly. The upper structure working mechanism includes a boom cylinder and a stick cylinder. The boom control valve assembly includes a first boom regeneration port. The stick control valve assembly includes a first stick regeneration port. The regeneration common oil circuit includes a first common oil circuit. The first boom regeneration port is fluidly connected to the first stick regeneration port through the first common oil circuit, and the first boom regeneration port is fluidly connected to the boom cylinder. The first stick regeneration port is fluidly connected to the inlet of the stick control valve assembly. The boom cylinder is configured to replenish oil to the first common oil circuit through the first boom regeneration port. The stick cylinder is configured to draw oil from the first common oil circuit through the first stick regeneration port.

[0019] In some embodiments, the boom control valve assembly further includes a first boom regeneration control valve. The first boom regeneration control valve is disposed between the boom cylinder and the first boom regeneration port. The first boom regeneration control valve is operable to open and close.

[0020] In some embodiments, the boom control valve assembly further includes a fourth boom regeneration port and a third boom regeneration control valve. The fourth boom regeneration port is fluidly connected to the boom cylinder. The third boom regeneration control valve is disposed between the fourth boom regeneration port and the boom cylinder, and the fourth boom regeneration port is fluidly connected to the common oil supply circuit. The third boom regeneration control valve is on / off. A portion of the return oil from the boom cylinder is configured to flow through the third boom regeneration control valve and the fourth boom regeneration port to the common oil supply circuit.

[0021] In some embodiments, the boom control valve assembly further includes a second boom regeneration port. The second boom regeneration port is fluidly connected to the inlet of the boom control valve assembly. The stick control valve assembly further includes a second stick regeneration port and a third stick regeneration port. The second stick regeneration port and the third stick regeneration port are fluidly connected to different working chambers of the stick cylinder, respectively. The regeneration common oil circuit further includes a second common oil circuit. The second common oil circuit is fluidly connected to the second boom regeneration port, the second stick regeneration port, and the third stick regeneration port. The stick cylinder is configured to replenish oil to the second common oil circuit through the second stick regeneration port and the third stick regeneration port. The boom cylinder is configured to draw oil from the second common oil circuit through the second boom regeneration port.

[0022] In some embodiments, the plurality of upper vehicle control valve assemblies further includes a bucket control valve assembly. The upper vehicle working mechanism includes a bucket cylinder. The bucket control valve assembly includes a first bucket regeneration port, which is fluidly connected to a first common oil circuit. The first bucket regeneration port is fluidly connected to the inlet of the bucket control valve assembly. The bucket cylinder is configured to draw oil from the first common oil circuit through the first bucket regeneration port.

[0023] In some embodiments, the boom control valve assembly further includes a second boom regeneration port and a third boom regeneration port. The second and third boom regeneration ports are fluidly connected to the inlet of the boom control valve assembly. The stick control valve assembly further includes a second stick regeneration port, a third stick regeneration port, and a fourth stick regeneration port. The second and third stick regeneration ports are fluidly connected to different working chambers of the stick cylinder. The fourth stick regeneration port is fluidly connected to the inlet of the stick control valve assembly. The bucket control valve assembly further includes a second bucket regeneration port, a third bucket regeneration port, and a fourth bucket regeneration port. The second bucket regeneration port is fluidly connected to the inlet of the bucket control valve assembly. The third and fourth bucket regeneration ports are fluidly connected to different working chambers of the bucket cylinder. The common oil supply circuit further includes a second common oil circuit and a third common oil circuit. The second common oil circuit is fluidly connected to the second boom regeneration port, the second stick regeneration port, the third stick regeneration port, and the second bucket regeneration port. The third common oil circuit is fluidly connected to the third regeneration oil port of the boom, the fourth regeneration oil port of the stick, the third regeneration oil port of the bucket, and the fourth regeneration oil port of the bucket.

[0024] In some embodiments, the stick control valve assembly further includes a first stick regeneration control valve and a second stick regeneration control valve. The first stick regeneration control valve is disposed between the second stick regeneration port and the stick cylinder. The second stick regeneration control valve is disposed between the third stick regeneration port and the stick cylinder. The first and second stick regeneration control valves are operable to be switched on and off. The bucket control valve assembly further includes a first bucket regeneration control valve and a second bucket regeneration control valve. The first bucket regeneration control valve is disposed between the third bucket regeneration port and the bucket cylinder. The second bucket regeneration control valve is disposed between the fourth bucket regeneration port and the bucket cylinder. The first and second bucket regeneration control valves are operable to be switched on and off.

[0025] In some embodiments, the excavator's hydraulic system further includes a common return oil circuit. This common return oil circuit is fluidly connected to the overhead control unit and the oil tank. Return oil from the overhead control unit flows to the oil tank via the common return oil circuit.

[0026] In some embodiments, the hydraulic system of the excavator further includes a slewing assembly. The slewing assembly includes a slewing control valve assembly and a slewing motor. The slewing control valve assembly drives the slewing motor. The pump assembly further includes a third oil pump connected in parallel. The third oil pump is fluidly connected to the inlet of the slewing control valve assembly. The return port of the slewing control valve assembly is fluidly connected to a common return oil circuit.

[0027] A second aspect of this application provides an excavator including the hydraulic system of the excavator as described above.

[0028] Based on the technical solution provided in this application, the hydraulic system of an excavator includes an oil tank, a pump assembly, an upper structure control assembly, an lower structure control assembly, a common oil supply circuit, and an oil regulating valve group. The pump assembly is fluidly connected to the oil tank and includes a first oil pump and a second oil pump connected in parallel. The upper structure control assembly is used to connect to and drive the upper structure working mechanism. The lower structure control assembly includes a left travel device and a right travel device. The common oil supply circuit is fluidly connected to the upper structure control assembly and is used to supply oil to the upper structure control assembly. The oil regulating valve group includes a left regulating inlet, a first left regulating inlet, a second left regulating inlet, a third left regulating inlet, a right regulating inlet, a first right regulating inlet, and a second right regulating inlet. The left regulating inlet is fluidly connected to the first oil pump. The right regulating inlet is fluidly connected to the second oil pump. The first and third left regulating inlets are both fluidly connected to the left travel device. The second left regulating inlet is fluidly connected to the common oil supply circuit. The first right regulating inlet is fluidly connected to the right travel device. The second right oil regulating port is fluidly connected to the common oil supply circuit. The left oil regulating port is connected to the second left oil regulating port. The right oil regulating port is connected to the first right oil regulating port. The oil regulating valve assembly has a first operating state and a second operating state. In the first operating state, the left oil regulating port is configured to also be connected to the first left oil regulating port, and the right oil regulating port is configured to also be connected to the second right oil regulating port. The first oil pump supplies oil to the common oil supply circuit and the left travel device. The second oil pump supplies oil to the common oil supply circuit and the right travel device. In the second operating state, the left oil regulating port is configured to also be connected to the second right oil regulating port, and the right oil regulating port is configured to also be connected to the third left oil regulating port. The first oil pump supplies oil to the common oil supply circuit, and the second oil pump supplies oil to the left travel device and the right travel device. By controlling the oil regulating valve group, the pump assembly supplies oil to either the upper or lower vehicle control assembly. When either the upper or lower vehicle control assembly is operating independently, the oil regulating valve group is in its first operating state, where both the first and second oil pumps supply oil to the upper or lower vehicle control assembly. When both the upper and lower vehicle control assemblies are operating simultaneously, the oil regulating valve group is in its second operating state, where the first oil pump supplies oil to the upper vehicle control assembly and the second oil pump supplies oil to the lower vehicle control assembly. This allows for independent oil supply to the upper and lower vehicle circuits, reducing the risk of deviation caused by inconsistent flow rates between the left and right travel devices and improving overall coordination. The elimination of the need for an integrated multi-way valve simplifies the hydraulic system's piping layout and reduces piping losses.

[0029] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0031] Figure 1 This is an overall schematic diagram of the hydraulic system of an excavator according to some embodiments of this application.

[0032] Figure 2 for Figure 1 A schematic diagram of the oil regulating valve assembly.

[0033] Figure 3 for Figure 1 A schematic diagram of the disembarkation control components.

[0034] Figure 4 for Figure 1 A schematic diagram of the boom control valve assembly.

[0035] Figure 5 for Figure 1 A schematic diagram of the overall vehicle control components.

[0036] Figure 6 for Figure 1 A schematic diagram of the back pressure check valve assembly. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0039] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0040] To address the shortcomings of existing technologies, improve the coordination between the excavator's upper and lower sections, increase flow utilization, and reduce fuel consumption, this application provides a hydraulic system for an excavator, referencing... Figure 1 and Figure 2The system includes an oil tank 1, a pump assembly, an upper vehicle control assembly, an lower vehicle control assembly, a common oil supply circuit H, and an oil regulating valve assembly 5. The pump assembly is fluidly connected to the oil tank 1 and includes a first oil pump 21 and a second oil pump 22 connected in parallel. The upper vehicle control assembly is used to connect to and drive the upper vehicle working mechanism. The lower vehicle control assembly includes a left travel device and a right travel device. The common oil supply circuit H is fluidly connected to the upper vehicle control assembly and is used to supply oil to the upper vehicle control assembly. The oil regulating valve assembly 5 includes a left regulating inlet 51, a first left regulating inlet 52, a second left regulating inlet 53, a third left regulating inlet 54, a right regulating inlet 55, a first right regulating inlet 56, and a second right regulating inlet 57. The left regulating inlet 51 is fluidly connected to the first oil pump 21. The right regulating inlet 55 is fluidly connected to the second oil pump 22. The first left regulating inlet 52 and the third left regulating inlet 54 are both fluidly connected to the left travel device. The second left regulating port 53 is fluidly connected to the common oil supply line H. The first right regulating port 56 is fluidly connected to the right travel device. The second right regulating port 57 is fluidly connected to the common oil supply line H. The left regulating port 51 is connected to the second left regulating port 53. The right regulating port 55 is connected to the first right regulating port 56. The regulating valve group 5 has a first operating state and a second operating state. In the first operating state, the left regulating port 51 is configured to also be connected to the first left regulating port 52, and the right regulating port 55 is configured to also be connected to the second right regulating port 57. The first oil pump 21 supplies oil to the common oil supply line H and the left travel device. The second oil pump 22 supplies oil to the common oil supply line H and the right travel device. In the second operating state, the left oil inlet 51 is configured to also connect with the second right oil inlet 57, and the right oil inlet 55 is configured to also connect with the third left oil inlet 54. The first oil pump 21 supplies oil to the common oil supply circuit H, and the second oil pump 22 supplies oil to the left and right travel devices. By controlling the oil regulating valve group 5, the oil pump assembly supplies oil to the upper vehicle control assembly or the lower vehicle control assembly. When the upper vehicle control assembly or the lower vehicle control assembly works alone, the oil regulating valve group 5 is in the first operating state. At this time, the first oil pump 21 and the second oil pump 22 jointly supply oil to the upper vehicle control assembly or the lower vehicle control assembly. When the upper vehicle control assembly and the lower vehicle control assembly work simultaneously, the oil regulating valve group 5 is in the second operating state. The first oil pump 21 supplies oil to the upper vehicle control assembly, and the second oil pump 22 supplies oil to the lower vehicle control assembly. This realizes that the upper and lower vehicle circuits are supplied with oil independently, reducing the risk of travel deviation caused by the inconsistent flow of the left and right travel devices and improving the overall coordination. The elimination of the need for an integrated multi-way valve simplifies the piping layout of the hydraulic system and reduces piping losses.

[0041] Specifically, refer to Figure 3The left travel device includes a left travel motor 41M, and the right travel device includes a right travel motor 42M. The left travel device includes a left oil inlet 41a and a left oil return port 41b. The right travel device includes a right oil inlet 42a and a right oil return port 42b. The left and right oil return ports 41b and 42b are connected and fluidly connected to the oil tank 1. The left oil inlet 41a supplies oil to the left travel motor 41M, and the right oil inlet 42a supplies oil to the right travel motor 42M. Taking the left travel motor 41M as an example, the left travel motor 41M has a first motor oil port and a second motor oil port. The left travel device also includes a left lower vehicle control valve group, a left first working oil port 41c and a left second working oil port 41d. The left first working oil port 41c is fluidly connected to the first motor oil port, and the left second working oil port 41d is fluidly connected to the second motor oil port. The left lower vehicle control valve group controls the lower vehicle left inlet 41a to connect with the left first working oil port 41c or the left second working oil port 41d, so that the oil flows through the left travel motor 41M in the forward or reverse direction, thereby realizing the forward or backward movement of the whole vehicle.

[0042] More specifically, still refer to Figure 3 The left lower vehicle control valve group includes a first lower vehicle on / off valve 411, a second lower vehicle on / off valve 412, a third lower vehicle on / off valve 413, and a fourth lower vehicle on / off valve 414. The oil outlet of the first on / off valve 411 is connected to the left lower vehicle return oil port 41b, and the oil inlet of the first on / off valve 411 is connected to the left first working oil port 41c and the oil outlet of the second lower vehicle on / off valve 412. The oil inlet of the second lower vehicle on / off valve 412 is fluidly connected to the left lower vehicle inlet port 41a and the oil inlet of the third lower vehicle on / off valve 413, the oil outlet of the third lower vehicle on / off valve 413 is connected to the left second working oil port 41d and the oil inlet of the fourth lower vehicle on / off valve 414, and the oil outlet of the fourth lower vehicle on / off valve 414 is connected to the left lower vehicle return oil port 41b. When the left travel device moves forward, the internal oil circuits of the second and fourth off-center valves 412 and 414 are connected, while the internal oil circuits of the first and third off-center valves 411 and 413 are disconnected. The oil flows through the left inlet 41a, the second off-center valve 412, and the first working port 41c to the left travel motor 41M, and then flows back to the oil tank through the second working port 41d, the fourth off-center valve 414, and the left return port 41b. When the left travel device reverses, the internal oil circuits of the first and third off-center valves 411 and 413 are connected, while the internal oil circuits of the second and fourth off-center valves 412 and 414 are disconnected. Oil flows through the left inlet 41a, the third off-center valve 413, and the second working port 41d to the left travel motor 41M, and then returns to the oil tank through the first working port 41c, the first off-center valve 411, and the left return port 41b. The structure and working principle of the right travel device are the same as those of the left travel device and will not be described further.

[0043] refer to Figure 2 In some embodiments, the left oil inlet 51 and the right oil inlet 55 are oscillatingly connected within the oil regulating valve assembly 5. In the second operating state, when there is a pressure difference between the common oil supply line H and the left and / or right travel devices, the left oil inlet 51 and the right oil inlet 55 are connected to allow mutual oil replenishment between the common oil supply line H and the lowering control assembly. Specifically, in the second operating state, the upper and lower vehicles operate simultaneously. If a pressure difference exists between the common oil supply line H and the lower vehicle, for example, if the pressure in the common oil supply line H is greater than the pressure in the lower vehicle, the left oil inlet 51 and the right oil inlet 55 are connected. At this time, the high-pressure oil from the upper vehicle flows to the lower vehicle to replenish the lower vehicle's oil supply, achieving full utilization of the oil and reducing overall machine consumption. Furthermore, when controlling the lowering action independently in the first operating state, if the upper action is suddenly started, the flow rate supplied to the lowering action by the pump assembly will decrease, causing a significant slowdown in the lowering action and noticeable discomfort to the operator. In this case, switching to the second operating state allows the left oil inlet 51 and the right oil inlet 55 to be connected within the oil regulating valve assembly 5 based on the pressure difference between the upper and lower actions. This allows the high-pressure oil from the upper action to flow to the lower action, ensuring the lowering action speed and improving the overall coordination of the vehicle. Similarly, when controlling the upper action independently, if the lower action suddenly slows down the upper action, the lower action can replenish oil to the upper action to ensure coordination between the two vehicles.

[0044] refer to Figure 2 In some embodiments, the oil regulating valve group 5 includes a first control valve group and a second control valve group. The first control valve group includes a first oil outlet and a second oil outlet. The oil inlet of the first control valve group is fluidly connected to the left oil regulating inlet 51. The first oil outlet is fluidly connected to the first left oil regulating inlet 52. The second oil outlet is fluidly connected to the second right oil regulating inlet 57. The second control valve group includes a third oil outlet and a fourth oil outlet. The oil inlet of the second control valve group is fluidly connected to the right oil regulating inlet 55. The third oil outlet is fluidly connected to the third left oil regulating inlet 54. The fourth oil outlet is fluidly connected to the second right oil regulating inlet 57. In a first operating state, the oil inlet of the first control valve group is connected to the first oil outlet, and the oil inlet of the second control valve group is connected to the fourth oil outlet. In a second operating state, the oil inlet of the first control valve group is connected to the second oil outlet, and the oil inlet of the second control valve group is connected to the third oil outlet. That is, by controlling the oil inlet of the first control valve group to connect with the first oil outlet or the second oil outlet, and controlling the oil inlet of the second control valve group to connect with the third oil outlet or the fourth oil outlet, the first working state and the second working state and switching are realized simply and efficiently.

[0045] refer to Figure 2In some embodiments, the first control valve group includes a first on / off valve 5a1 and a second on / off valve 5a2. The second control valve group includes a third on / off valve 5b1 and a fourth on / off valve 5b2. The oil inlet of the first on / off valve 5a1 is fluidly connected to the left oil inlet 51, the oil inlet of the second on / off valve 5a2, and the second left oil adjusting port 53. The oil outlet of the first on / off valve 5a1 is fluidly connected to the first left oil adjusting port 52. The oil outlet of the second on / off valve 5a2 is fluidly connected to the second right oil adjusting port 57. The oil inlet of the third on / off valve 5b1 is fluidly connected to the right oil inlet 55, the oil inlet of the fourth on / off valve 5b2, and the first right oil adjusting port 56. The oil outlet of the fourth on / off valve 5b2 is fluidly connected to the second right oil adjusting port 57. In the first operating state, the internal oil passages of the first on / off valve 5a1 and the fourth on / off valve 5b2 are connected, while the internal oil passages of the second on / off valve 5a2 and the third on / off valve 5b1 are disconnected. In the second operating state, the internal oil circuits of the second on-off valve 5a2 and the third on-off valve 5b1 are connected, while the internal oil circuits of the first on-off valve 5a1 and the fourth on-off valve 5b2 are disconnected.

[0046] refer to Figure 2 In some embodiments, the oil regulating valve assembly further includes a replenishing oil circuit and a replenishing oil on / off valve 5c. The replenishing oil circuit is located between the outlet of the second on / off valve 5a2 and the outlet of the third on / off valve 5b1. The replenishing oil on / off valve 5c is located on the replenishing oil circuit. In the second operating state, when there is a pressure difference between the common oil supply circuit H and the left travel device and / or the right travel device, the replenishing oil on / off valve 5c is activated to allow mutual oil replenishment between the common oil supply circuit H and the undercarriage control component. Specifically, the excavator's hydraulic system also includes a pressure sensor 8, which is used to detect the pressure of various parts of the hydraulic system. When there is a pressure difference between the common oil supply circuit H and the undercarriage, the replenishing oil on / off valve 5c is activated. More specifically, pressure sensors 8 are installed at both the first and second motor oil ports of the left travel motor 41M, and pressure sensors 8 are also installed at the working mechanism of the upper vehicle control component. Since the oil of the upper vehicle control component is obtained from the common oil supply circuit H, when the pressure of the upper vehicle is detected to be greater than that of the lower vehicle, the oil in the common oil supply circuit H flows to the lower vehicle to achieve pressure balance between the upper and lower vehicles.

[0047] In some embodiments, the valve core opening of the oil replenishment on / off valve 5c is adjustable. When it is necessary to regenerate the flow rate of the upper vehicle to the flow rate of the lower vehicle, the internal oil circuit of the oil replenishment on / off valve 5c is connected and the valve core opening is adjusted according to the working conditions to regulate the flow rate of oil replenishment from the upper vehicle to the lower vehicle. Similarly, the flow rate of oil replenishment from the lower vehicle to the upper vehicle can also be adjusted to improve the controllability of the system.

[0048] refer to Figure 1 and Figure 5In some embodiments, the upper vehicle control assembly includes multiple upper vehicle control valve groups. The upper vehicle working mechanism includes multiple working cylinders, each fluidly connected to one of the multiple upper vehicle control valve groups. Oil output from the pump assembly flows through the regulating valve group 5 and the common oil supply line H to the multiple upper vehicle control valve groups to drive the multiple working cylinders. The excavator's hydraulic system also includes a regeneration common oil line. The multiple upper vehicle control valve groups are fluidly connected through the regeneration common oil line so that when a pressure difference exists between the multiple working cylinders, the multiple working cylinders replenish each other's oil through the regeneration common oil line. The multiple upper vehicle control valve groups are integrated together through the common oil supply line H, so that when the regulating valve group 5 is in its first working state, the oil output from the first oil pump 21 and the second oil pump 22 converges in the common oil supply line H, ensuring that each upper vehicle control valve group obtains oil from the common oil supply line H to ensure upper vehicle operation, optimizing the hydraulic system's piping layout, reducing pressure loss, and improving system efficiency. Furthermore, the regeneration common oil line between the various upper vehicle control valve groups enables flow regeneration, further saving energy. (Reference) Figure 5 In some embodiments, multiple upper-mounted control valve assemblies include a boom control valve assembly 31 and a stick control valve assembly 32. The upper-mounted working mechanism includes a boom cylinder and a stick cylinder. The boom control valve assembly 31 includes a first boom regeneration port 311. The stick control valve assembly 32 includes a first stick regeneration port 321. A regeneration common oil circuit includes a first common oil circuit R1. The first boom regeneration port 311 is fluidly connected to the first stick regeneration port 321 via the first common oil circuit R1, and the first boom regeneration port 311 is fluidly connected to the boom cylinder. The first stick regeneration port 321 is fluidly connected to the inlet of the stick control valve assembly 32. The boom cylinder is configured to replenish oil to the first common oil circuit R1 through the first boom regeneration port 311. The stick cylinder is configured to draw oil from the first common oil circuit R1 through the first stick regeneration port 321. Specifically, when the load on the boom cylinder is too large, the oil in the boom cylinder can be replenished to the stick cylinder through the first regeneration oil port 321 of the boom, the first common oil circuit R1, and the first regeneration oil port 321 of the stick, thereby accelerating the response speed of the stick cylinder and improving the overall working efficiency of the machine.

[0049] refer to Figure 4 More specifically, the boom control valve assembly 31 has an oil inlet P, an oil return port T, a working oil port A, and a working oil port B. Working oil port A is connected to the large chamber of the boom cylinder, and working oil port B is connected to the small chamber of the boom cylinder. Oil inlet P is connected to the common oil supply circuit H, and oil return port T is connected to the oil tank 1. The boom first regeneration oil port 311 is fluidly connected to working oil port B. When the boom and stick move, under the action of the excavation load, when the small chamber of the boom cylinder is compressed to a pressure greater than that in the common oil supply circuit H, the oil returning from the small chamber of the boom cylinder can be regenerated and sent to the stick cylinder, increasing the stick cylinder's movement speed.

[0050] refer to Figure 4In some embodiments, the boom control valve assembly 31 further includes a first boom regeneration control valve 31a. The first boom regeneration control valve 31a is disposed between the boom cylinder and the first boom regeneration port 311, and is operable to open and close. Specifically, the inlet of the first boom regeneration control valve 31a is fluidly connected to the working port B, and the outlet of the first boom regeneration control valve 31a is fluidly connected to the first boom regeneration port 311. The first boom regeneration control valve 31a is opened or closed according to the load condition of the boom cylinder, improving controllability.

[0051] refer to Figure 4 In some embodiments, the boom control valve assembly 31 further includes a first boom on / off valve 31d, a second boom on / off valve 31e, a third boom on / off valve 31f, and a fourth boom on / off valve 31g. The oil inlet P is fluidly connected to the oil inlets of the second boom on / off valve 31e and the third boom on / off valve 31f. The oil outlet of the second boom on / off valve 31e is fluidly connected to both the oil inlet and the working oil port A of the first boom on / off valve 31d. The oil outlet of the first boom on / off valve 31d is fluidly connected to the return oil port T. The oil outlet of the third boom on / off valve 31f is fluidly connected to both the oil inlet and the working oil port B of the fourth boom on / off valve 31g. The oil outlet of the fourth boom on / off valve 31g is fluidly connected to the return oil port T. When the boom is raised, the internal oil circuits of the second boom shut-off valve 31e and the fourth boom shut-off valve 31g are connected, while the internal oil circuits of the first boom shut-off valve 31d and the third boom shut-off valve 31f are disconnected. Oil enters the small chamber of the boom cylinder through the inlet P, the second boom shut-off valve 31e, and the working port A to push the piston rod out. Return oil flows back to the oil tank 1 through the working port B, the fourth boom shut-off valve 31g, and the return port T. When the boom is lowered, the internal circuits of the first boom shut-off valve 31d and the third boom shut-off valve 31f are connected, while the internal oil circuits of the second boom shut-off valve 31e and the third boom shut-off valve 31g are disconnected. Oil enters the small chamber of the boom cylinder through the inlet P, the third boom shut-off valve 31f, and the working port B to retract the piston rod. Return oil flows back to the oil tank through the working port A, the first boom shut-off valve 31d, and the return port T.

[0052] To further improve the completeness of the flow regeneration function of the hydraulic system, refer to Figure 4Based on the above embodiments, the boom control valve assembly 31 further includes a fourth boom regeneration port 314 and a third boom regeneration control valve 31c. The fourth boom regeneration port 314 is fluidly connected to the boom cylinder. The third boom regeneration control valve 31c is disposed between the fourth boom regeneration port 314 and the boom cylinder, and the fourth boom regeneration port 314 is fluidly connected to the common oil supply circuit H. The third boom regeneration control valve 31c is configured to be on and off. A portion of the return oil from the boom cylinder is configured to flow to the common oil supply circuit H through the third boom regeneration control valve 31c and the fourth boom regeneration port 314. This portion of the return oil from the boom cylinder can be regenerated to the common oil supply circuit H, ensuring sufficient oil flow to other parts of the boom control assembly and improving efficiency. For example, the fourth regeneration oil port 314 of the boom is fluidly connected to the working oil port A. When the boom is lowered, oil enters the small chamber of the boom cylinder, and part of the return oil from the large chamber flows to the return oil port T through the first boom on / off valve 31d. At this time, the internal oil circuit of the third boom regeneration control valve 31c is connected, allowing another part of the return oil to flow to the common oil supply circuit H through the third boom regeneration control valve 31c and the fourth boom regeneration oil port 314. This part of the return oil can flow to the inlet of the stick control valve group 32 through the common oil supply circuit H, ensuring sufficient oil supply to the stick cylinder, accelerating the stick's movement speed, and improving the overall compound movement speed of the excavator. In this embodiment, the first boom regeneration control valve 31a needs to be in the off state.

[0053] In some embodiments, the boom control valve assembly 31 further includes a second boom regeneration control valve 31b. The inlet of the third boom regeneration control valve 31c is fluidly connected to the inlet of the second boom regeneration control valve 31b, and the outlet of the second boom regeneration control valve 31b is fluidly connected to the working port B. By controlling the on / off state of the second boom regeneration control valve 31b, a portion of the return oil from the large chamber of the boom cylinder can be regenerated to the small chamber of the boom cylinder through the second boom regeneration control valve 31b, reducing the risk of motion stoppage (cavitation) in the small chamber of the boom cylinder due to insufficient oil supply when the boom cylinder descends too quickly, and improving system reliability and coordination. In this embodiment, the first boom regeneration control valve 31a needs to be in the off state.

[0054] In addition, during the operation of the boom or bucket, such as during excavation, the reaction force of the ground will cause the excavator to leave the ground, which will increase the pressure in the small chamber of the boom cylinder. At this time, the pressure oil in the small chamber of the boom cylinder can flow to the first common oil circuit R1 through the boom first regeneration control valve 31a, thereby replenishing the oil in the boom cylinder or bucket cylinder and realizing the excavation speed increase.

[0055] refer to Figure 4In some embodiments, a check valve is also provided between the oil inlet of the first regeneration control valve 31a, the oil outlet of the second regeneration control valve 31b, and the working oil port B and the return oil port T, so that the oil can be replenished to the small cavity of the boom cylinder through the return oil port T, the check valve, and the working oil port B, and the oil in the small cavity of the boom cylinder can be prevented from flowing directly to the oil tank 1, thereby improving stability.

[0056] refer to Figure 4 In some embodiments, the boom control valve assembly 31 further includes a load holding valve 31h. The load holding valve 31h is used to maintain the stability of the boom in a specific position and prevent the boom from lowering or moving due to external interference or other factors. Specifically, the load holding valve 31h is located between the oil outlet of the second boom on / off valve 31e and the working oil port A, and the control chamber of the load holding valve 31h is connected to the third boom on / off valve 31f through a pilot oil circuit. When the boom is raised, the oil flows out from the oil outlet of the second boom on / off valve 31e and flows forward through the load holding valve 102 to the working oil port A. When the boom is lowered, the oil, after passing through the third boom on / off valve 31f, enters the control chamber of the load holding valve 31h through the pilot oil circuit to open the load holding valve 31h in the reverse direction, so that the return oil from the large chamber of the boom cylinder flows in the reverse direction through the load holding valve 31h to the first boom control valve 31d, and then flows to the return oil port T. Of course, when the boom second regeneration control valve 31b is in the connected state, the return oil from the large chamber of the boom cylinder, after passing through the load holding valve 31h in the reverse direction, can flow to the small chamber of the boom cylinder through the boom second regeneration control valve 31b. Alternatively, when the boom third regeneration control valve 31c is in the connected state, the return oil from the large chamber of the boom cylinder, after passing through the load holding valve 31h in the reverse direction, can flow to the common oil supply circuit H through the boom third regeneration control valve 31c.

[0057] refer to Figure 4In some embodiments, the boom control valve assembly 31 further includes a second boom regeneration port 312. The second boom regeneration port 312 is fluidly connected to the inlet of the boom control valve assembly 31. The stick control valve assembly 32 further includes a second stick regeneration port 322 and a third stick regeneration port 323. The second stick regeneration port 322 and the third stick regeneration port 323 are fluidly connected to different working chambers of the stick cylinder, respectively. The regeneration common oil circuit also includes a second common oil circuit R2. The second common oil circuit R2 is fluidly connected to the second boom regeneration port 312, the second stick regeneration port 322, and the third stick regeneration port 323. The stick cylinder is configured to replenish oil to the second common oil circuit R2 through the second stick regeneration port 322 and the third stick regeneration port 323. The boom cylinder is configured to draw oil from the second common oil circuit R2 through the second boom regeneration port 312. Specifically, the second regeneration oil port 322 of the boom is fluidly connected to the small cavity of the boom cylinder, and the third regeneration oil port 323 of the boom is fluidly connected to the large cavity of the boom cylinder. This arrangement allows oil to be replenished to the second common oil circuit R2 through the third regeneration oil port 323 or the second regeneration oil port 322 of the boom when the large or small cavity of the boom is overloaded. It also allows the boom control valve group 31 to draw oil through the second regeneration oil port 312 of the boom, thereby regenerating the oil in the boom control valve group 32 to the boom control valve group 31, accelerating the action speed of the boom cylinder, and improving the overall efficiency of the machine.

[0058] refer to Figure 5 In some embodiments, the multiple upper control valve assemblies also include a bucket control valve assembly 33. The upper working mechanism includes a bucket cylinder. The bucket control valve assembly 33 includes a first bucket regeneration port 331. The first bucket regeneration port 331 is fluidly connected to a first common oil passage R1. The first bucket regeneration port 331 is fluidly connected to the oil inlet of the bucket control valve assembly 33. The bucket cylinder is configured to draw oil from the first common oil passage R1 through the first bucket regeneration port 331. Specifically, when the load on the boom cylinder is too high, oil can also be regenerated to the bucket cylinder through the first boom regeneration port 311, the first common oil passage R1, and the first bucket regeneration port 331, thereby increasing the bucket digging speed and improving the overall machine efficiency.

[0059] The internal structure of the boom control valve assembly 32 and the bucket control valve assembly 33 can be referred to the above description of the boom control valve assembly 31. This allows the oil to flow into the boom control valve assembly 32 or the bucket control valve assembly 33 and then flow to the large and small chambers of the boom cylinder or the bucket cylinder in a controlled manner to complete different actions. Furthermore, both the boom control valve assembly 32 and the bucket control valve assembly 33 can achieve internal flow regeneration, thereby accelerating the action speed of their respective cylinders. The specific details will not be elaborated further.

[0060] refer to Figure 5In some embodiments, the boom control valve assembly 31 further includes a third boom regeneration port 313. The third boom regeneration port 313 is fluidly connected to the inlet of the boom control valve assembly 31. The stick control valve assembly 32 further includes a fourth stick regeneration port 324. The fourth stick regeneration port 324 is fluidly connected to the inlet of the stick control valve assembly 32. The bucket control valve assembly 33 further includes a second bucket regeneration port 332, a third bucket regeneration port 333, and a fourth bucket regeneration port 334. The second bucket regeneration port 332 is fluidly connected to the inlet of the bucket control valve assembly 33 and is also fluidly connected to the second common oil circuit R2. The third bucket regeneration port 333 and the fourth bucket regeneration port 334 are respectively fluidly connected to different working chambers of the bucket cylinder. The common oil supply circuit also includes a third common oil circuit R3. The third common oil circuit R3 is fluidly connected to the boom third regeneration oil port 313, the stick fourth regeneration oil port 324, the bucket third regeneration oil port 333, and the bucket fourth regeneration oil port 334. The flow rates of the boom control valve group 31, the stick control valve group 32, and the bucket control valve group 33 can regenerate each other, improving the overall machine efficiency, saving the output flow of the pump components, and achieving energy saving for the entire machine.

[0061] Specifically, in some embodiments, the third regeneration oil port 333 of the bucket is fluidly connected to the small cavity of the bucket cylinder, and the fourth regeneration oil port 334 of the bucket is fluidly connected to the large cavity of the bucket cylinder. When controlling the bucket movement, if the pressure in a certain working cavity of the bucket cylinder is too high, oil can be supplied to the third common oil circuit R3 through the third regeneration oil port 333 or the fourth regeneration oil port 334 of the bucket, so that this part of the oil is regenerated to the boom control valve group 31 and the stick control valve group 32.

[0062] More specifically, in some embodiments, the stick cylinder is configured to swing outward when oil is introduced into its small chamber, the bucket cylinder is configured to swing outward when oil is introduced into its small chamber, and the small chamber of the stick cylinder is configured to be fluidly connected to the second regeneration oil port 322 of the stick, the large chamber of the stick cylinder is configured to be fluidly connected to the third regeneration oil port 323 of the stick, the small chamber of the bucket cylinder is configured to be fluidly connected to the third regeneration oil port 333 of the bucket, and the large chamber of the bucket cylinder is configured to be fluidly connected to the fourth regeneration oil port 334 of the bucket. When the boom is lowered and the stick and bucket are swung outwards to achieve leveling by controlling the boom control valve group 31, the stick control valve group 32, and the bucket control valve group 33, a sudden load impact during the stick's leveling process will cause the pressure in the small chamber of the stick cylinder to suddenly increase. At this time, the flow rate in the small chamber of the stick cylinder can be regenerated to the boom control valve group 31 and the bucket control valve group 33 through the second regeneration port 322 and the second common oil circuit R2. Correspondingly, the pressure in the small chamber of the bucket cylinder will also increase, and the flow rate in the small chamber of the bucket cylinder can be regenerated to the boom control valve group 31 and the stick control valve group 32 through the third common oil circuit R3, thereby increasing the leveling speed. Alternatively, when the boom is raised, the stick retracts, and the bucket retracts to achieve leveling by controlling the boom control valve group 31, the stick control valve group 32, and the bucket control valve group 33, a sudden load impact during the bucket retraction leveling process will cause a sudden increase in the pressure of the large chamber of the bucket cylinder. At this time, the flow rate of the large chamber of the bucket cylinder can be regenerated to the boom control valve group 31 and the stick control valve group 32 through the third regeneration port 333 and the third common oil circuit R3. Correspondingly, the pressure of the large chamber of the stick cylinder will also suddenly increase. At this time, the flow rate of the large chamber of the stick cylinder can be regenerated to the boom control valve group 31 and the bucket control valve group 33 through the second common oil circuit R2. Therefore, the coordination between various parts of the hydraulic system can be improved, and the leveling speed can be increased.

[0063] refer to Figure 5In some embodiments, the stick control valve assembly 32 further includes a first stick regeneration control valve 32a and a second stick regeneration control valve 32b. The first stick regeneration control valve 32a is disposed between the second stick regeneration port 322 and the stick cylinder. The second stick regeneration control valve 32b is disposed between the third stick regeneration port 323 and the stick cylinder. The first stick regeneration control valve 32a and the second stick regeneration control valve 32b are operable to be switched on and off. The bucket control valve assembly 33 further includes a first bucket regeneration control valve 33a and a second bucket regeneration control valve 33b. The first bucket regeneration control valve 33a is disposed between the third bucket regeneration port 333 and the bucket cylinder. The second bucket regeneration control valve 33b is disposed between the fourth bucket regeneration port 334 and the bucket cylinder. The first bucket regeneration control valve 33a and the second bucket regeneration control valve 33b are operable to be switched on and off. Specifically, the pressure sensor 8 includes a boom cylinder sensor, a stick cylinder sensor, and a bucket cylinder sensor, each corresponding to the boom cylinder, stick cylinder, and bucket cylinder, respectively. Based on the sensors of each cylinder, the connection or disconnection of the first stick regeneration control valve 32a, the second stick regeneration control valve 32b, the first bucket regeneration control valve 33a, and the second bucket regeneration control valve 33b is controlled, thereby achieving flow regeneration between the various components and improving controllability.

[0064] For example, when the pressure in the boom cylinder is detected to be greater than the pressure in the stick cylinder, the boom cylinder sensor controls the boom first regeneration control valve 31a to open, so that the oil in the small chamber of the boom cylinder is regenerated through the boom first regeneration control valve 31a to the first common oil circuit R1 to supply oil to the stick control valve assembly 32. The control strategies of the stick cylinder sensor and the bucket cylinder sensor are the same as those of the boom cylinder sensor, and will not be described in detail here.

[0065] refer to Figure 1 In some embodiments, the excavator's hydraulic system also includes a common return oil circuit L. The common return oil circuit L is fluidly connected to the upper control assembly and the oil tank 1. The return oil from the upper control assembly flows to the oil tank 1 through the common return oil circuit L. Specifically, the common return oil circuit L is connected to the return ports of the boom control valve assembly 31, the stick control valve assembly 32, and the bucket control valve assembly 33, allowing the upper control assembly to centrally return oil to the oil tank 1 through the common return oil circuit L, optimizing the piping layout of the hydraulic system and reducing pressure loss.

[0066] To improve the safety of hydraulic systems, refer to Figure 1 and Figure 6The excavator's hydraulic system also includes a back pressure check valve assembly. This assembly is located between the common return oil circuit L and the oil tank 1. The back pressure check valve assembly includes a main back pressure check valve 91 and a secondary back pressure check valve 92 connected in reverse parallel. The main back pressure check valve 91 is configured to allow one-way flow of return oil from the common return oil circuit L towards the oil tank 1. The lower-car left return oil port 41b and the lower-car right return oil port 42b are both fluidly connected to the oil circuit between the back pressure check valve assembly and the common return oil circuit L, ensuring that the return oil from both the lower-car control components and the upper-car control components flows through the main back pressure check valve 91 and back to the oil tank 1, thereby maintaining the back pressure level of the hydraulic system. The secondary back pressure check valve 92 is configured to replenish oil from the oil tank 1 to the lower-car control components and the common return oil circuit L when the pressure in the lower-car control components and the common return oil circuit L is lower than the pressure in the oil tank 1, preventing cavitation in the actuators.

[0067] Based on the above embodiments, refer to Figure 1 The excavator's hydraulic system also includes a cooler C. Cooler C is located between the back pressure check valve assembly and the oil tank 1. Cooler C is used to reduce the temperature of the hydraulic fluid, provide stable operating conditions, extend the service life of hydraulic components, and ensure the reliability and stability of the hydraulic system.

[0068] refer to Figure 6 In some embodiments, the excavator's hydraulic system further includes an anti-clogging oil circuit and an anti-clogging check valve 10. The first end of the anti-clogging oil circuit is fluidly connected to the oil circuit between the back pressure check valve assembly and the cooler C, and the second end of the anti-clogging oil circuit is fluidly connected to the oil circuit between the cooler C and the oil tank 1. The anti-clogging check valve 10 is located on the anti-clogging oil circuit and configured to allow one-way flow of oil towards the oil tank 1. Specifically, the opening pressure of the anti-clogging check valve 10 is greater than the opening pressure of the back pressure main check valve 91. When the cooler C is not blocked, the oil passes through the back pressure main check valve 91 and preferentially flows through the cooler C for heat dissipation. When the cooler C is blocked, the return oil, after flowing through the back pressure check valve assembly, can flow back to the oil tank 1 through the anti-clogging check valve 10, improving the system's safety and stability.

[0069] To reduce the return oil back pressure and further achieve energy savings, refer to Figure 5 In some embodiments, the return port of the boom control valve group 32 is not connected to the common return oil circuit L, but is directly connected to the oil tank 1, so that the return oil from the boom cylinder flows directly back to the oil tank 1 without passing through the back pressure control valve group.

[0070] refer to Figure 1 In some embodiments, the hydraulic system of the excavator also includes a high-pressure accumulator 71 and a low-pressure accumulator 72. The high-pressure accumulator 71 is connected to the common oil supply circuit H, serving as an auxiliary power source, storing circuit energy, stabilizing high pressure, and improving system energy efficiency; the low-pressure accumulator 72 is connected to the common oil return circuit L, stabilizing return oil pressure and improving the system's oil replenishment stability.

[0071] refer to Figure 1 In some embodiments, the excavator's hydraulic system also includes a slewing assembly. The slewing assembly includes a slewing control valve group 61 and a slewing motor 62. The slewing control valve group 61 drives the slewing motor 62 to rotate the excavator. The pump assembly also includes a third pump 23 connected in parallel with the first pump 21 and the second pump 22. The third pump 23 is fluidly connected to the inlet of the slewing control valve group 61. The return port of the slewing control valve group 61 is fluidly connected to the common return oil passage L. Specifically, the third pump 23 is configured to independently supply oil to the slewing motor 62. In conventional excavators, the main pump supplies oil to various parts of the hydraulic system by controlling the flow direction of the internal oil passage of an integrated multi-way valve. When the main pump simultaneously supplies oil to the slewing and other actuators, the hydraulic oil will preferentially flow to the slewing due to the higher pressure of the other actuators and the lower pressure of the slewing, causing the operation of the other actuators to slow down. To maintain coordination during the combined actions of the slewing and other actuators, a throttle valve is typically added between the other actuators and the slewing mechanism to reduce the amount of hydraulic oil supplied from the main pump to the slewing mechanism and ensure the amount of hydraulic oil output from the main pump to the other actuators. However, throttle valves can cause energy waste. In this embodiment, the slewing assembly is independently controlled, reducing the significant energy loss caused by the throttle valve during the combined actions of the slewing and other actuators, thus saving oil consumption.

[0072] In some embodiments, the pressure sensor includes a rotary pressure sensor corresponding to the rotary motor 62 to display the pressure of the rotary motor and improve controllability.

[0073] In some embodiments, the slewing control valve assembly 61 includes a plurality of slewing on / off valves. By controlling the connection or disconnection of the internal oil passages of the plurality of slewing on / off valves, the oil supply from the third oil pump 23 flows through the slewing motor 62 in the forward or reverse direction, causing the slewing motor to rotate forward or in reverse. The arrangement of the plurality of slewing on / off valves can be referred to as the boom first on / off valve 31d to boom fourth on / off valve 31g in the boom control valve assembly 31, and will not be described in detail here.

[0074] In some embodiments, the swing motor 62 is configured as an electric drive motor, in which case the pump assembly in the excavator's hydraulic system consists of a first oil pump 21 and a second oil pump 22 connected in parallel. That is, the control of the swing section is changed from hydraulic drive to electric drive. Only the hydraulically driven motor needs to be replaced with an electric drive motor. Since the integrated multi-way valve is eliminated, no modifications are required to the lower control assembly, the upper control assembly, or the internal components of the oil regulating valve group 5, thus improving the overall machine's functionality and expansion flexibility.

[0075] In some embodiments, the multiple oil pumps in the pump assembly are driven by the engine of the whole machine, or the multiple oil pumps in the pump assembly are powered by electric drive, for example, by a battery and a motor to power the first oil pump 21, the second oil pump 22 and the third oil pump 23 connected in parallel.

[0076] In some embodiments, the first oil pump 21, the second oil pump 22, and the third oil pump 23 are connected in series and are driven by independent motors to supply oil to the upper vehicle control component, the lower vehicle control component, and the slewing component, respectively.

[0077] The various control valves and on / off valves involved in the embodiments of this application (e.g., the first regeneration control valve 31a and the first on / off valve 5a1 of the boom) can be electromagnetic directional valves or high-speed switching valves to improve controllability.

[0078] Based on the above embodiments, the integrated multi-way valve in the prior art has been eliminated, and the independent design of the undercarriage control component, boom control valve group 31, stick control valve group 32, bucket control valve group 33 and slewing component has been realized. The pipeline layout of the whole machine hydraulic system has been optimized, oil pressure loss has been reduced, and the completeness of the flow regeneration function between various parts has been improved.

[0079] This application also provides an excavator including the hydraulic system of the excavator described above. The excavator provided by this application can improve the coordination of the excavator's loading and unloading, thereby increasing operational efficiency.

[0080] The hydraulic system for excavators provided in this application can also be applied to other types of construction machinery besides excavators.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them; although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this application or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in this application.

Claims

1. A hydraulic system for an excavator, characterized in that, include: Fuel tank (1); The pump assembly, which is fluidly connected to the oil tank (1), includes a first oil pump (21) and a second oil pump (22) arranged in parallel. A loading control component is used to connect to the loading working mechanism and drive the loading working mechanism to operate. The disembarkation control assembly includes a left-side travel mechanism and a right-side travel mechanism; A common oil supply line (H), fluidly connected to the upper vehicle control assembly, is used to supply oil to the upper vehicle control assembly; and The oil regulating valve assembly (5) includes a left oil regulating port (51), a first left oil regulating port (52), a second left oil regulating port (53), a third left oil regulating port (54), a right oil regulating port (55), a first right oil regulating port (56), a second right oil regulating port (57), a first control valve assembly, and a second control valve assembly. The left oil regulating port (51) is fluidly connected to the first oil pump (21), the right oil regulating port (55) is fluidly connected to the second oil pump (22), and both the first left oil regulating port (52) and the third left oil regulating port (54) are fluidly connected to the left travel device. The second left oil adjustment port (53) is fluidly connected to the common oil supply line (H), the first right oil adjustment port (56) is fluidly connected to the right travel device, the second right oil adjustment port (57) is fluidly connected to the common oil supply line (H), the left oil adjustment inlet port (51) is connected to the second left oil adjustment port (53), the right oil adjustment inlet port (55) is connected to the first right oil adjustment port (56), the first control valve group includes a first oil outlet and a second oil outlet, the oil inlet of the first control valve group is fluidly connected to the left oil adjustment inlet port (51), and the first oil outlet is fluidly connected to the second right travel device. A left oil regulating port (52) is fluidly connected, and a second oil outlet is fluidly connected to a second right oil regulating port (57). The second control valve group includes a third oil outlet and a fourth oil outlet. The oil inlet of the second control valve group is fluidly connected to the right oil regulating inlet (55). The third oil outlet is fluidly connected to the third left oil regulating port (54), and the fourth oil outlet is fluidly connected to the second right oil regulating port (57). The oil regulating valve group (5) has a first working state and a second working state. In the first working state, the oil inlet of the first control valve group is connected to the first oil outlet. The oil inlet of the second control valve group is connected to the fourth oil outlet. The first oil pump (21) supplies oil to the common oil supply line (H) and the left travel device. The second oil pump (22) supplies oil to the common oil supply line (H) and the right travel device. In the second working state, the oil inlet of the first control valve group is connected to the second oil outlet. The oil inlet of the second control valve group is connected to the third oil outlet. The first oil pump (21) supplies oil to the common oil supply line (H). The second oil pump (22) supplies oil to the left travel device and the right travel device.

2. The hydraulic system of the excavator according to claim 1, characterized in that, Within the oil regulating valve assembly (5), the left oil regulating port (51) and the right oil regulating port (55) are connected in a way that allows for switching on and off. In the second operating state, when there is a pressure difference between the common oil supply circuit (H) and the left travel device and / or the right travel device, the left oil regulating port (51) and the right oil regulating port (55) are connected to allow the common oil supply circuit (H) and the vehicle disembarkation control assembly to replenish each other with oil.

3. The hydraulic system of the excavator according to claim 1, characterized in that, The first control valve group includes a first on / off valve (5a1) and a second on / off valve (5a2). The second control valve group includes a third on / off valve (5b1) and a fourth on / off valve (5b2). The oil inlet of the first on / off valve (5a1) is fluidly connected to the left oil inlet (51), the oil inlet of the second on / off valve (5a2), and the second left oil inlet (53). The oil outlet of the first on / off valve (5a1) is fluidly connected to the first left oil inlet (52). The oil outlet of the second on / off valve (5a2) is fluidly connected to the second right oil inlet (57). The oil inlet of the third on / off valve (5b1) is fluidly connected to the right oil inlet (5a2). 5) The oil inlet of the fourth on-off valve (5b2) and the first right adjustment port (56) are fluidly connected, and the oil outlet of the fourth on-off valve (5b2) is fluidly connected to the second right adjustment port (57). In the first working state, the internal oil circuits of the first on-off valve (5a1) and the fourth on-off valve (5b2) are connected, and the internal oil circuits of the second on-off valve (5a2) and the third on-off valve (5b1) are disconnected. In the second working state, the internal oil circuits of the second on-off valve (5a2) and the third on-off valve (5b1) are connected, and the internal oil circuits of the first on-off valve (5a1) and the fourth on-off valve (5b2) are disconnected.

4. The hydraulic system of the excavator according to claim 3, characterized in that, The oil regulating valve group also includes an oil replenishment circuit and an oil replenishment on / off valve (5c). The oil replenishment circuit is located between the oil outlet of the second on / off valve (5a2) and the oil outlet of the third on / off valve (5b1). The oil replenishment on / off valve (5c) is located on the oil replenishment circuit. In the second working state, when there is a pressure difference between the common oil supply circuit (H) and the left travel device and / or the right travel device, the oil replenishment on / off valve (5c) is connected to allow the common oil supply circuit (H) and the alighting control component to replenish each other with oil.

5. The hydraulic system of the excavator according to claim 1, characterized in that, The upper vehicle control assembly includes multiple upper vehicle control valve groups, and the upper vehicle working mechanism includes multiple working cylinders that are fluidly connected to the multiple upper vehicle control valve groups respectively. The oil output by the pump assembly flows to the multiple upper vehicle control valve groups through the oil regulating valve group (5) and the common oil supply line (H) to drive the multiple working cylinders to move respectively. The hydraulic system of the excavator also includes a regeneration common oil line. The multiple upper vehicle control valve groups are fluidly connected through the regeneration common oil line so that when there is a pressure difference between the multiple working cylinders, the multiple working cylinders replenish each other with oil through the regeneration common oil line.

6. The hydraulic system of the excavator according to claim 5, characterized in that, The plurality of upper vehicle control valve groups include a boom control valve group (31) and a stick control valve group (32). The upper vehicle working mechanism includes a boom cylinder and a stick cylinder. The boom control valve group (31) includes a boom first regeneration port (311), and the stick control valve group (32) includes a stick first regeneration port (321). The regeneration common oil circuit includes a first common oil circuit (R1). The boom first regeneration port (311) is connected to the stick first regeneration port (321) through the first common oil circuit (R1). The regeneration port (321) is fluidly connected, and the first regeneration port (311) of the boom is fluidly connected to the boom cylinder. The first regeneration port (321) of the stick is fluidly connected to the inlet of the stick control valve group (32). The boom cylinder is configured to replenish oil to the first common oil circuit (R1) through the first regeneration port (311), and the stick cylinder is configured to draw oil from the first common oil circuit (R1) through the first regeneration port (321).

7. The hydraulic system of the excavator according to claim 6, characterized in that, The boom control valve group (31) further includes a boom first regeneration control valve (31a), which is located between the boom cylinder and the boom first regeneration port (311) and can be switched on and off.

8. The hydraulic system of the excavator according to claim 6, characterized in that, The boom control valve assembly (31) further includes a fourth boom regeneration port (314) and a third boom regeneration control valve (31c). The fourth boom regeneration port (314) is fluidly connected to the boom cylinder. The third boom regeneration control valve (31c) is located between the fourth boom regeneration port (314) and the boom cylinder, and the fourth boom regeneration port (314) is fluidly connected to the common oil supply circuit (H). The third boom regeneration control valve (31c) is configured to be on and off. A portion of the return oil from the boom cylinder is configured to flow to the common oil supply circuit (H) through the third boom regeneration control valve (31c) and the fourth boom regeneration port (314).

9. The hydraulic system of the excavator according to claim 6, characterized in that, The boom control valve assembly (31) further includes a second boom regeneration port (312), which is fluidly connected to the inlet of the boom control valve assembly (31). The stick control valve assembly (32) further includes a second stick regeneration port (322) and a third stick regeneration port (323), which are fluidly connected to different working chambers of the stick cylinder, respectively. The regeneration common oil circuit also includes a second common... The oil passage (R2) is fluidly connected to the second regeneration oil port (312) of the boom, the second regeneration oil port (322) of the stick, and the third regeneration oil port (323) of the stick. The stick cylinder is configured to replenish oil to the second common oil passage (R2) through the second regeneration oil port (322) and the third regeneration oil port (323) of the stick. The boom cylinder is configured to draw oil from the second common oil passage (R2) through the second regeneration oil port (312) of the boom.

10. The hydraulic system of the excavator according to claim 6, characterized in that, The plurality of upper vehicle control valve groups also include a bucket control valve group (33), the upper vehicle working mechanism includes a bucket cylinder, the bucket control valve group (33) includes a bucket first regeneration oil port (331), the bucket first regeneration oil port (331) is fluidly connected to the first common oil circuit (R1), the bucket first regeneration oil port (331) is fluidly connected to the oil inlet of the bucket control valve group (33), and the bucket cylinder is configured to draw oil from the first common oil circuit (R1) through the bucket first regeneration oil port (331).

11. The hydraulic system of the excavator according to claim 10, characterized in that, The boom control valve assembly (31) further includes a second boom regeneration port (312) and a third boom regeneration port (313), which are fluidly connected to the inlet of the boom control valve assembly (31). The stick control valve assembly (32) further includes a second stick regeneration port (322), a third stick regeneration port (323), and a fourth stick regeneration port (324), which are fluidly connected to different working chambers of the stick cylinder. The fourth stick regeneration port (324) is fluidly connected to the inlet of the stick control valve assembly (32). The bucket control valve assembly (33) further includes a second bucket regeneration port (332), a third bucket regeneration port (333), and a fourth bucket regeneration port (324). The second regenerated oil port (332) of the bucket is fluidly connected to the oil inlet of the bucket control valve group (33). The third regenerated oil port (333) and the fourth regenerated oil port (334) of the bucket are fluidly connected to different working chambers of the bucket cylinder. The common oil supply circuit also includes a second common oil circuit (R2) and a third common oil circuit (R3). The second common oil circuit (R2) is fluidly connected to the second regenerated oil port (312) of the boom, the second regenerated oil port (322) of the stick, the third regenerated oil port (323) of the stick and the second regenerated oil port (332) of the bucket. The third common oil circuit (R3) is fluidly connected to the third regenerated oil port (313) of the boom, the fourth regenerated oil port (324) of the stick, the third regenerated oil port (333) of the bucket and the fourth regenerated oil port (334) of the bucket.

12. The hydraulic system of the excavator according to claim 11, characterized in that, The boom control valve group (32) further includes a first boom regeneration control valve (32a) and a second boom regeneration control valve (32b). The first boom regeneration control valve (32a) is located between the second boom regeneration port (322) and the boom cylinder, and the second boom regeneration control valve (32b) is located between the third boom regeneration port (323) and the boom cylinder. The first boom regeneration control valve (32a) and the second boom regeneration control valve (32b) can be switched on and off. The bucket control valve group (33) further includes a first bucket regeneration control valve (33a) and a second bucket regeneration control valve (33b). The first bucket regeneration control valve (33a) is located between the third bucket regeneration port (333) and the bucket cylinder, and the second bucket regeneration control valve (33b) is located between the fourth bucket regeneration port (334) and the bucket cylinder. The first bucket regeneration control valve (33a) and the second bucket regeneration control valve (33b) can be switched on and off.

13. The hydraulic system of the excavator according to any one of claims 1 to 12, characterized in that, It also includes a common oil return line (L), which is fluidly connected to the upper vehicle control component and the oil tank (1), and the oil return from the upper vehicle control component flows to the oil tank (1) through the common oil return line (L).

14. The hydraulic system of the excavator according to claim 13, characterized in that, It also includes a slewing assembly, which includes a slewing control valve group (61) and a slewing motor (62). The slewing control valve group (61) is used to drive the slewing motor (62) to make the excavator slewing. The pump assembly also includes a third oil pump (23) arranged in parallel. The third oil pump (23) is fluidly connected to the oil inlet of the slewing control valve group (61), and the oil return port of the slewing control valve group (61) is fluidly connected to the common oil return circuit (L).

15. An excavator, characterized in that, The hydraulic system of the excavator as described in any one of claims 1 to 14.

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