Hydraulic control system, excavator hydraulic system control method, and excavator

Abstract

The present application relates to the technical field of excavators, and in particular to a hydraulic control system, a hydraulic system control method of an excavator and the excavator. The hydraulic control system comprises: a main control unit comprising a plurality of working pumps; a rotating unit independently arranged from the main control unit, the rotating unit comprising a rotating pump, a rotating control valve and a rotating actuator; the rotating pump is in communication with a first pipeline and a second pipeline arranged in parallel; the rotating unit and a merging element are arranged in the first pipeline, the second pipeline is in communication with an oil path pumped by at least one working pump; and the merging element is used to control the rotating action of the rotating unit and the flow distribution of the first pipeline and the second pipeline. By controlling the merging element, the present application realizes that the rotating pump independently pumps oil to the rotating actuator via the first pipeline, thereby ensuring the stability of the rotating flow; meanwhile, the oil discharged from the rotating pump to the second pipeline can be used to make the action actuator obtain additional flow, thereby appropriately increasing the speed of other actions and effectively improving the overall efficiency of the machine.

Description

Technical Field

[0001] This invention relates to the field of excavator technology, and in particular to a hydraulic control system, an excavator hydraulic system control method, and an excavator. Background Technology

[0002] With economic development and social progress, energy conservation has become an inevitable trend and a social consensus. As equipment used in infrastructure construction, mining, and other construction operations, the working efficiency and fuel economy of hydraulic excavators have always been important performance indicators.

[0003] A typical excavator's hydraulic system includes a main pump, multi-way directional valves, and drive units that execute various actions. For hydraulic excavators, the swing hydraulic system is a crucial component. The hydraulic fluid discharged from the main pump tends to flow towards lower-load circuits. Therefore, in hydraulic excavators using traditional open-loop swing hydraulic systems, during multi-action compound operations, especially those involving swing, the fixed total volume of fluid discharged by the main pump reduces the flow rate to the boom circuit, resulting in slower boom movement. Furthermore, the swing motion is subject to high load during startup and braking, and low load during constant speed, causing unstable boom speed variations. This necessitates frequent control of the multi-way directional valves to stabilize the boom speed. Similarly, the swing motion is affected in the same way, impacting excavator operating efficiency and operator experience. Moreover, existing hydraulic excavators exhibit low efficiency when performing compound actions involving swing. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a hydraulic control system, a hydraulic system control method for an excavator, and an excavator, so as to solve the problems of decreased boom speed, unstable speed change, and low working efficiency of existing hydraulic excavators when performing compound actions involving slewing.

[0005] A first aspect of the present invention provides a hydraulic control system, wherein the hydraulic control system comprises:

[0006] The main control unit includes multiple working pumps;

[0007] A rotary unit is set up independently of the main control unit; the rotary unit includes a rotary pump, a rotary control valve, and a rotary actuator; the rotary pump is connected to a first pipeline and a second pipeline arranged in parallel; the rotary unit is set on the first pipeline, and the second pipeline is connected to an oil circuit pumped by at least one of the working pumps;

[0008] A confluence element, disposed in the first pipeline, is used to control whether the rotary unit can perform a rotary action and to distribute the flow rate of oil in the first pipeline and the second pipeline.

[0009] Preferably, the oil circuit pumped by the working pump includes a central oil circuit and a parallel oil circuit, and the second pipeline is connected to the parallel oil circuit.

[0010] Preferably, a first flow control valve is provided on the first pipeline, so that the oil in the first pipeline is passed to the rotary actuator via the rotary pump;

[0011] A second flow control valve is provided on the second pipeline, so that the oil in the second pipeline is passed to the main control unit via the rotary pump.

[0012] Preferably, the merging element is an electrically controlled two-position two-way valve, which has a first valve position for connecting the first pipeline and a second valve position for disconnecting the first pipeline.

[0013] Preferably, the merging element is a hydraulically controlled check valve.

[0014] Preferably, the rotary control valve is disposed between the rotary pump and the rotary actuator along the flow direction of the oil in the first pipeline;

[0015] The merging element is located upstream or downstream of the rotary control valve.

[0016] Preferably, the working pump includes a first main pump and a second main pump;

[0017] The main control unit also includes a main valve block, which has a main valve left connection and a main valve right connection. The first main pump is connected to the main valve left connection, and the second main pump is connected to the main valve right connection, so that the oil circuits output by the first main pump and the second main pump are set in parallel.

[0018] The second pipeline is connected to the oil lines output by the first main pump and the second main pump, respectively.

[0019] Preferably, the main control unit includes:

[0020] The boom unit has a boom single-stage reversing valve and a boom double-stage reversing valve;

[0021] The boom unit has a boom single-stage reversing valve and a boom double-stage reversing valve;

[0022] The bucket unit has a single bucket directional valve and a double bucket directional valve;

[0023] The travel unit has a left travel reversing valve and a right travel reversing valve;

[0024] The boom double reversing valve, the stick single reversing valve, the bucket double reversing valve, and the left travel reversing valve are all located on the left side of the main valve.

[0025] The boom reversing valve, the stick reversing valve, the bucket reversing valve, and the right travel reversing valve are all located on the right side of the main valve.

[0026] A second aspect of the present invention provides a method for controlling a hydraulic system of an excavator, implemented using the hydraulic control system described in any of the above-mentioned technical solutions, the method comprising:

[0027] When the excavator is not performing a slewing action, the confluence element is closed, so there is no oil flow in the first pipeline, and the slewing pump can pump the oil to the second pipeline;

[0028] When the excavator is only performing the slewing action, the confluence component is activated, and the slewing pump only pumps oil into the first pipeline;

[0029] When the excavator performs a combined action including slewing, the confluence device is activated, and the slewing pump simultaneously pumps oil to the first and second pipelines. By adjusting the valve core position of the confluence device, the flow rate of oil in the first and second pipelines is distributed.

[0030] A third aspect of the present invention provides an excavator including the hydraulic control system described in any of the above technical solutions.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] The hydraulic control system of the present invention sets up the rotary unit independently of the main control unit. By controlling the confluence element, the rotary pump can independently pump oil to the rotary actuator via the first pipeline, ensuring the stability of the rotary flow rate. In addition, the second pipeline is connected to the oil circuit pumped by at least one working pump in the main control unit. Thus, when performing a compound action involving rotary motion, by controlling the confluence element, the rotary pump can independently pump oil to the rotary actuator via the first pipeline, thereby ensuring that the rotary motion does not affect the speed of other actions and that the rotary speed is not affected by other actions. While ensuring the stability of the slewing flow rate, the oil discharged from the slewing pump to the second pipeline can be fully utilized to appropriately increase the speed of other actions; or when performing compound actions without slewing, the oil discharged from the slewing pump flows through the second pipeline and is distributed to each action actuator by the main control unit, so that each action actuator receives additional flow, thereby increasing the action speed. In this way, the flow rate of the slewing pump can be effectively utilized to improve the overall efficiency of the excavator while saving energy, so that the excavator performance can be effectively utilized and the service life of the excavator can be extended.

[0033] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 A hydraulic schematic diagram of a hydraulic control system provided in Embodiment 1 of the present invention;

[0036] Figure 2 A hydraulic schematic diagram of a hydraulic control system provided in Embodiment 2 of the present invention;

[0037] Figure 3 Hydraulic schematic diagram of the hydraulic control system provided in Embodiment 3 of the present invention;

[0038] Figure 4 The hydraulic schematic diagram of the hydraulic control system provided in Embodiment 4 of the present invention.

[0039] Icons: 10-Slewing pump; 11-Slewing control valve; 12-Slewing actuator; 13-Merging component; 14-First flow direction control valve; 15-Second flow direction control valve; 16-First pipeline; 17-Second pipeline; 100-First main pump; 200-Second main pump; 300-Central oil circuit; 400-Parallel oil circuit; 501-Left main valve connection; 502-Right main valve connection; 503-Boom single-phase directional valve; 504-Stick single-phase directional valve; 505-Bucket single-phase directional valve; 506-Left travel directional valve; 507-Double boom directional valve; 508-Double stick directional valve; 509-Double bucket directional valve; 510-Right travel directional valve. Detailed Implementation

[0040] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0041] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0042] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0043] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0044] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0045] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0046] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0047] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0048] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0049] According to a first aspect of the present invention, a hydraulic control system is provided, which includes a main control unit, a rotary unit, and a confluence element 13.

[0050] Example 1

[0051] In this embodiment, as Figure 1 As shown, the main control unit includes a working pump and a main valve block. The main control unit can control the actuators of the stick movement, bucket movement, boom movement and travel movement to perform corresponding actions. The actuator for the stick movement is the stick cylinder, the actuator for the bucket movement is the bucket cylinder, the actuator for the boom movement is the boom cylinder, and the actuator for the travel movement is the travel motor.

[0052] In this embodiment, as Figure 1 As shown, the main control unit has multiple working pumps. Specifically, the working pumps include a first main pump 100 and a second main pump 200. The main valve block has a left main valve connection 501 and a right main valve connection 502. The first main pump 100 is connected to the left main valve connection 501, and the second main pump 200 is connected to the right main valve connection 502, so that the oil circuits output by the first main pump 100 and the second main pump 200 are connected in parallel. However, the number of working pumps is not limited to two; more can be set according to actual needs.

[0053] Furthermore, in this embodiment, the main control unit includes a boom unit, a stick unit, a bucket unit, and a traveling unit. The boom unit has a boom single-stage reversing valve 503 and a boom double-stage reversing valve 507; the stick unit has a stick single-stage reversing valve 504 and a stick double-stage reversing valve 508; the bucket unit has a bucket single-stage reversing valve 505 and a bucket double-stage reversing valve 509; and the traveling unit has a left traveling reversing valve 506 and a right traveling reversing valve 510. The boom double-stage reversing valve 507, the stick single-stage reversing valve 504, the bucket double-stage reversing valve 509, and the left traveling reversing valve 506 are all located on the left side of the main valve 501; the boom single-stage reversing valve 503, the stick double-stage reversing valve 508, the bucket single-stage reversing valve 505, and the right traveling reversing valve 510 are all located on the right side of the main valve 502. When the actuators driven in the left main valve 501 and the right main valve 502 are the same, the specific actions of the actuators are also the same. For example, taking the bucket unit as an example, when the bucket first reversing valve 505 is in the right position and the bucket second reversing valve 509 is in the left position, oil can be supplied to the large chamber of the bucket cylinder at the same time, so as to control the same action of the bucket.

[0054] In this embodiment, as Figure 1 As shown, the slewing unit is set up independently of the main control unit. The slewing unit includes a slewing pump 10, a slewing control valve 11, and a slewing actuator 12. Specifically, the slewing pump 10 is connected to the first pipeline 16 and the second pipeline 17, which are arranged in parallel. The slewing unit is set on the first pipeline 16, and the second pipeline 17 is connected to the oil circuit pumped by at least one working pump. This allows the slewing pump 10 to pump oil to the slewing actuator 12 through the first pipeline 16 and to supply oil to the actuators of the stick movement, bucket movement, boom movement, and travel movement in the main control unit through the second pipeline 17.

[0055] Specifically, in this embodiment, along the flow direction of the oil in the first pipeline 16, the rotary control valve 11 is disposed between the rotary pump 10 and the rotary actuator 12. The rotary actuator can be a rotary motor, and the rotary control valve 11 can be an electromagnetic directional valve, which has high control accuracy, good stability and flexibility.

[0056] Furthermore, in this embodiment, as Figure 1 As shown, the confluence element 13 is disposed in the first pipeline 16 and is used to control whether the rotary unit can perform a rotary action and to distribute the flow rate of the oil in the first pipeline 16 and the second pipeline 17. In this embodiment, the confluence element 13 is a valve-type component, and a valve core is disposed inside the confluence element 13. By controlling the position change of the valve core inside the confluence element 13, the flow rate distribution of the oil in the first pipeline 16 and the second pipeline 17 is realized.

[0057] Specifically, the confluence element 13 is an electrically controlled two-position two-way valve, which has a first valve position for connecting to the first pipeline 16 and a second valve position for disconnecting the first pipeline 16. Figure 1 The diagram shows the confluence element 13 in the first valve position. In a preferred embodiment, the confluence element 13 is an electrically controlled valve, thus allowing the confluence element 13 to be directly connected to the electrical control system, enabling the confluence element 13 and the rotary control valve 11 to be controlled together via the electrical control system.

[0058] In this embodiment, the confluence element 13 is disposed upstream of the rotary control valve 11.

[0059] The working principles of an excavator performing different actions are as follows:

[0060] When the excavator performs a compound action without slewing, the confluence element 13 is in the closed state. The oil discharged by the slewing pump 10 flows through the second pipeline 17 and is distributed by the main control unit to each action actuator (i.e., the aforementioned stick cylinder, bucket cylinder, boom cylinder and / or travel motor), so that each action actuator obtains additional flow, i.e., the flow output through the non-working pump, thereby increasing the speed of each action.

[0061] When the excavator only performs the slewing action, the confluence member 13 is in the open state. The confluence member 13 controls all the oil discharged by the slewing pump 10 to be transported to the slewing actuator 12 through the first pipeline 16 so that the excavator can perform the slewing action. The slewing pump 10 can independently pump oil to the slewing actuator 12 through the first pipeline 16 to ensure the stability of the slewing flow.

[0062] When the excavator performs a compound action involving slewing, the confluence member 13 is in the open state. The slewing pump 10 can independently pump oil to the slewing actuator 12 via the first pipeline 16, thereby ensuring that the slewing action does not affect the speed of other actions and that the slewing speed is not affected by other actions. The confluence member 13 also distributes the flow of oil in the first pipeline 16 and the second pipeline 17. Specifically, the valve core of the confluence member 13 has an opening area characteristic. By adjusting the opening area of ​​the valve core, the flow is distributed. In this way, while ensuring a stable slewing speed, the oil discharged by the slewing pump 10 into the second pipeline 17 can be fully utilized to appropriately increase the speed of other actions, thereby improving the working efficiency of the excavator and the operator's operating experience.

[0063] In a preferred embodiment, the second pipeline 17 is connected to the oil lines output by the first main pump 100 and the second main pump 200, respectively, so as to ensure that when the excavator performs compound actions, the oil supplied by the rotary pump 10 can additionally increase the speed of each action.

[0064] In this embodiment, the rotary pump 10, the first main pump 100, and the second main pump 200 can all be piston pumps. Piston pumps have the advantages of high driving power, high rated pressure, high speed, and high efficiency to meet the usage requirements of construction machinery (such as excavators).

[0065] Furthermore, such as Figure 1 As shown, each working pump pumps an oil circuit including a central oil circuit 300 and a parallel oil circuit 400. The working pump can be connected to the actuator controlled by the main control unit via the parallel oil circuit 400. In this embodiment, the second pipeline 17 is connected to the parallel oil circuit 400, thus ensuring that the oil pumped by the rotary pump 10 via the second pipeline 17 can merge with the oil in the parallel oil circuit 400, and thus be jointly delivered to the actuator that needs to perform the action.

[0066] Furthermore, in this embodiment, such as Figure 1 As shown, a check valve is installed on the parallel oil circuit 400. The connection between the second pipeline 17 and the parallel oil circuit 400 is located downstream of the check valve, thereby ensuring that the flow direction of the oil output through the second pipeline 17 can merge with the oil in the parallel oil circuit 400, and then be delivered to the actuator controlled by the main control unit, instead of flowing to the central oil circuit 300.

[0067] In this embodiment, as Figure 1 As shown, a first flow control valve 14 is provided on the first pipeline 16, allowing the oil in the first pipeline 16 to flow only to the rotary actuator 12 via the rotary pump 10; a second flow control valve 15 is provided on the second pipeline 17, allowing the oil in the second pipeline 17 to flow only to the main control unit via the rotary pump 10, thereby determining the flow direction of the oil in the first pipeline 16 and the second pipeline 17. In this embodiment, the first flow control valve 14 and the second flow control valve 15 can be selected as check valves.

[0068] Example 2

[0069] The principle of the hydraulic control system in this embodiment is described in [reference needed]. Figure 2 As shown. The difference between Embodiment 2 and Embodiment 1 is that the confluence element 13 is located downstream of the rotary control valve 11. This arrangement can also meet the control requirements of the hydraulic control system for the rotary oil circuit.

[0070] Example 3

[0071] The principle of the hydraulic control system in this embodiment is described in [reference needed]. Figure 3 As shown. The difference between Embodiment 3 and Embodiment 1 is that the confluence element 13 is a hydraulically controlled check valve. The hydraulically controlled check valve is suitable for mechanical equipment operating in harsh working environments and meets the working environment requirements of excavators.

[0072] Example 4

[0073] The principle of the hydraulic control system in this embodiment is described in [reference needed]. Figure 4 As shown. The difference between Embodiment 4 and Embodiment 2 is that the confluence element 13 is a hydraulically controlled check valve to meet the working requirements of excavators operating in harsh environments.

[0074] According to the hydraulic control system of the present invention, the rotary unit is set independently of the main control unit. By controlling the confluence element, the rotary pump can independently pump oil to the rotary actuator via the first pipeline, ensuring the stability of the rotary flow rate. In addition, the second pipeline is connected to the oil circuit pumped by at least one working pump in the main control unit. Thus, when performing a compound action involving rotary motion, by controlling the confluence element, the rotary pump can independently pump oil to the rotary actuator via the first pipeline, thereby not affecting the speed of other actions and the rotary speed is not affected by other actions. While ensuring the stability of the rotary flow rate, the oil discharged by the rotary pump to the second pipeline can also be fully utilized to appropriately increase the speed of other actions. Alternatively, when performing a compound action without rotary motion, the oil discharged by the rotary pump flows to each actuator via the second pipeline and is distributed by the main control unit, so that each actuator receives additional flow, thereby increasing the action speed.

[0075] A second aspect of the present invention provides a hydraulic system control method for an excavator, applied to the implementation of the aforementioned hydraulic control system.

[0076] In this embodiment, the excavator hydraulic system control method includes:

[0077] When the excavator is not performing a slewing action, the confluence component is closed, resulting in no oil flow in the first pipeline; however, the slewing pump can pump oil into the second pipeline, so that when the excavator performs other actions without slewing, the oil in the second pipeline can merge with the oil in the parallel oil circuit, and thus be jointly delivered to the corresponding actuator, allowing the actuator to obtain additional flow and thereby increasing the operating speed;

[0078] When the excavator is only performing the slewing action, the confluence component is activated, and the slewing pump only pumps oil into the first pipeline to ensure the stability of the slewing flow rate.

[0079] When the excavator performs a compound action including slewing, the confluence device opens, and the slewing pump simultaneously pumps oil to both the first and second pipelines. By adjusting the valve core position of the confluence device, the flow distribution of oil in the first and second pipelines is achieved. This ensures that the slewing pump, via the first pipeline, pumps oil to the slewing actuator, guaranteeing that the slewing action does not affect the speed of other actions, and that the slewing speed is unaffected by other actions. In this way, while ensuring a stable slewing speed, the oil discharged by the slewing pump to the second pipeline can be fully utilized to appropriately increase the speed of other actions. This solves the problem of wasted slewing pump power when there is no slewing action, while also increasing the speed of other actions, effectively utilizing the flow of the slewing pump to improve the overall operating efficiency of the machine.

[0080] A third aspect of the present invention provides an excavator equipped with a hydraulic control system. When only a slewing motion is performed, a confluence element is in an open state, allowing the slewing pump to independently pump oil to the slewing actuator via a first pipeline, ensuring the stability of the slewing flow rate. When performing a compound motion involving slewing, the confluence element is in an open state, allowing the slewing pump to independently pump oil to the slewing actuator via the first pipeline, thereby ensuring that the slewing motion does not affect the speed of other motions and that the slewing speed is unaffected by other motions. Furthermore, the confluence element is controlled to regulate the oil flow in both the first and second pipelines. The hydraulic fluid flow distribution ensures stable slewing speed while fully utilizing the oil discharged from the slewing pump to the second pipeline to appropriately increase the speed of other actions. When performing compound actions without slewing, the confluence element is closed, and the oil discharged from the slewing pump flows through the second pipeline and, under the distribution of the main control unit, to each action actuator, giving each actuator additional flow and thus increasing the speed of each action. This, in turn, improves the overall efficiency of the excavator while saving energy, effectively maximizing the excavator's performance and extending its service life.

[0081] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A hydraulic control system for controlling the actions of an excavator, characterized in that, The hydraulic control system includes: The main control unit includes multiple working pumps; A rotary unit is provided independently of the main control unit; the rotary unit includes a rotary pump, a rotary control valve, and a rotary actuator; the rotary pump is connected to a first pipeline and a second pipeline arranged in parallel; the rotary unit is located on the first pipeline, and the second pipeline is connected to an oil circuit pumped by at least one of the working pumps; the oil circuit pumped by the working pump includes a central oil circuit and parallel oil circuits, and the second pipeline is connected to the parallel oil circuits; A confluence element, disposed in the first pipeline, is used to control whether the rotary unit can perform a rotary action and to distribute the flow rate of oil in the first pipeline and the second pipeline; the confluence element distributes the flow rate by adjusting the opening area of ​​the valve core; When the rotary unit does not perform a rotary action, the confluence member is in a closed state, and the oil discharged by the rotary pump merges with the oil in the parallel oil circuit through the second pipeline; When the rotary unit only performs the rotary action, the confluence member is in the open state, and the confluence member controls all the oil discharged by the rotary pump to be transported to the rotary actuator through the first pipeline; When the rotary unit performs a compound action involving rotary motion, the confluence member is in the open state, and the flow rate of oil in the first pipeline and the second pipeline is distributed through the confluence member.

2. The hydraulic control system according to claim 1, characterized in that, A first flow control valve is provided on the first pipeline, so that the oil in the first pipeline is passed to the rotary actuator via the rotary pump; A second flow control valve is provided on the second pipeline, so that the oil in the second pipeline is passed to the main control unit via the rotary pump.

3. The hydraulic control system according to claim 1, characterized in that, The merging device is an electrically controlled two-position two-way valve, which has a first valve position for connecting the first pipeline and a second valve position for disconnecting the first pipeline.

4. The hydraulic control system according to claim 1, characterized in that, The merging element is a hydraulically controlled check valve.

5. The hydraulic control system according to claim 1, characterized in that, Along the direction of oil flow in the first pipeline, the rotary control valve is disposed between the rotary pump and the rotary actuator; The merging element is located upstream or downstream of the rotary control valve.

6. The hydraulic control system according to claim 1, characterized in that, The working pump includes a first main pump and a second main pump; The main control unit also includes a main valve block, which has a main valve left connection and a main valve right connection. The first main pump is connected to the main valve left connection, and the second main pump is connected to the main valve right connection, so that the oil circuits output by the first main pump and the second main pump are set in parallel. The second pipeline is connected to the oil lines output by the first main pump and the second main pump, respectively.

7. The hydraulic control system according to claim 6, characterized in that, The main control unit includes: The boom unit has a boom single-stage reversing valve and a boom double-stage reversing valve; The boom unit has a boom single-stage reversing valve and a boom double-stage reversing valve; The bucket unit has a single bucket directional valve and a double bucket directional valve; The travel unit has a left travel reversing valve and a right travel reversing valve; The boom double reversing valve, the stick single reversing valve, the bucket double reversing valve, and the left travel reversing valve are all located on the left side of the main valve. The boom reversing valve, the stick reversing valve, the bucket reversing valve, and the right travel reversing valve are all located on the right side of the main valve.

8. A control method for a hydraulic system of an excavator, characterized in that, The hydraulic system control method for the excavator, implemented according to any one of claims 1 to 7, comprises: When the excavator is not performing a slewing action, the confluence element closes, preventing oil flow in the first pipeline, allowing the slewing pump to pump the oil to the second pipeline. When the excavator is only performing the slewing action, the confluence component is activated, and the slewing pump only pumps oil into the first pipeline; When the excavator performs a combined action including slewing, the confluence device is activated, and the slewing pump simultaneously pumps oil to the first and second pipelines. By adjusting the valve core position of the confluence device, the flow rate of oil in the first and second pipelines is distributed.

9. An excavator, characterized in that, The hydraulic control system includes any one of claims 1 to 7.

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