Converging multi-way valve and dual pump hydraulic system

Abstract

The application discloses a combined multi-way valve and a double-pump hydraulic system. The combined multi-way valve comprises a load-sensitive unit, a bypass throttling unit and a combined control link. The load-sensitive unit comprises a first main working oil path provided with a first pumping oil inlet and a plurality of first working links connected in parallel with the first main working oil path. The bypass throttling unit comprises a second main working oil path provided with a second pumping oil inlet, and at least one second working link is arranged in the second main working oil path. The combined control link comprises a combined reversing valve and a pressure-limiting unloading valve. The combined reversing valve is used for switching the on-off between the second main working oil path and the first main working oil path, and the pressure-limiting unloading valve is used for controlling the oil return of the second main working oil path. The application can realize the combined scheme of the first pump telescopic, variable-amplitude and winch oil path load sensitivity and the second pump bypass throttling system, can realize the telescopic, variable-amplitude and winch low-pressure double-pump combination according to the engine power, and switches to single-pump oil supply in the high-pressure state, thereby improving the working efficiency. The structure and control of the whole valve body are simple, and the design cost is low.

Description

Technical Field

[0001] This application pertains to the field of cranes, and specifically relates to a hydraulic control system for a crane and a confluence multi-way valve used therein. Background Technology

[0002] Cranes typically involve multiple actions and their actuators, resulting in vastly different demands for flow rate and pressure. Existing single-pump systems struggle to meet all these requirements. Furthermore, some crane models are becoming increasingly smaller, limiting the range of suitable engines. At idle, insufficient torque often leads to stalling due to pressure buildup.

[0003] Using a single-pump system can easily result in slow speeds. Therefore, a partial solution is to use two pumps in a combined flow control mode. This prevents flameout under low pressure and ensures the required speed is met. While existing combined flow control systems can achieve high flow rates under light loads and low flow rates under heavy loads, balancing micro-motion and high efficiency, or enabling different levels of flow control to improve flow adaptability and save energy, or achieving smooth coordination of complex actions, these systems are often extremely complex in structure, expensive, and generally lack unloading protection for dangerous actions. Summary of the Invention

[0004] To overcome at least one of the aforementioned technical deficiencies, this application provides a confluence multi-way valve and a dual-pump hydraulic system, which has a simple valve body structure and achieves dual-pump confluence control at low cost.

[0005] A first aspect of this application provides a confluence multi-way valve, comprising:

[0006] The load-sensitive unit includes a first main working oil circuit with a first pumping oil inlet and a plurality of first working connections connected in parallel to the first main working oil circuit;

[0007] The bypass throttling unit includes a second main working oil circuit with a second pump inlet, and the second main working oil circuit has at least one second working connection.

[0008] The confluence control system includes a confluence reversing valve and a pressure relief valve. The confluence reversing valve is used to switch the connection between the second main working oil circuit and the first main working oil circuit. The pressure relief valve is used to control the return oil of the second main working oil circuit.

[0009] In some embodiments, the second working link includes a second directional control valve, the second main working oil circuit passes through the second directional control valve and is configured to be in an oil circuit open state in the cut-off neutral position of the second directional control valve and in an oil circuit closed state in the working directional control valve position.

[0010] In some embodiments, the bypass throttling unit includes a second return port, the second main working oil circuit is connected to the second return port through the pressure relief valve, and is connected in parallel to the first main working oil circuit through the confluence reversing valve.

[0011] In some embodiments, the confluence control link includes an anti-backflow check valve for preventing oil from flowing to the confluence reversing valve. The anti-backflow check valve is disposed in the first main working oil circuit and located at the valve front end of the confluence reversing valve.

[0012] In some embodiments, the load-sensitive unit includes a load feedback control oil circuit, each of the first working links includes a first actuation directional valve and a pressure reducing valve, the first outlet end of each of the pressure reducing valves is respectively connected to the load feedback control oil circuit, and the inlet end of the pressure reducing valve is connected to the first main working oil circuit through the first actuation directional valve and is configured to be in an oil circuit closed state when the first actuation directional valve is in the closed position and in an oil circuit open state when the working directional valve is in the working position.

[0013] In some embodiments, the merging directional valve and the pressure-limiting unloading valve are hydraulically controlled directional valves, and the load feedback control oil circuit is connected as a pilot control oil circuit to the respective control chambers of the merging directional valve and the pressure-limiting unloading valve.

[0014] In some embodiments, the merging directional valve and the pressure relief valve are hydraulically controlled directional valves, and the hydraulically controlled terminals are both connected to the second outlet terminal of the pressure reducing valve.

[0015] In some embodiments, the load-sensitive unit includes a first return oil port, and an unloaded oil circuit is connected between the first main working oil circuit and the first return oil port. The unloaded oil circuit is provided with a three-way flow valve, and the two control chambers on both sides of the three-way flow valve are respectively connected to the load feedback control oil circuit and the first main working oil circuit.

[0016] In some embodiments, the load-sensitive unit includes a first return oil port, and an emergency unloading oil circuit is connected between the first main working oil circuit and the first return oil port, wherein an unloading valve is provided in the emergency unloading oil circuit.

[0017] In some embodiments, the unloading valve is a cartridge valve, and the control oil circuit of the cartridge valve is equipped with a solenoid ball valve.

[0018] According to a second aspect of this application, a dual-pump hydraulic system is provided, comprising:

[0019] The aforementioned confluence multi-way valve;

[0020] A load-sensitive variable pump is used to supply oil to the inlet of the first pump;

[0021] A gear pump is used to supply oil to the oil inlet of the second pump.

[0022] In this application, the confluence multi-way valve comprises three functional parts: a load-sensing unit, a bypass throttling unit, and a confluence control linkage. The confluence directional valve in the confluence control linkage is used to switch the connection between the second and first main working oil circuits, while the pressure-limiting and unloading valve controls the return oil from the second main working oil circuit. This enables a confluence scheme between the load-sensing system of the first pump's telescopic, luffing, and hoisting oil circuits and the bypass throttling system of the second pump. Specifically, by utilizing the pressure-limiting and unloading valve, low-pressure dual-pump confluence for telescopic, luffing, and hoisting oil circuits can be achieved based on engine power, while switching to single-pump oil supply in high-pressure conditions improves working efficiency. The overall structure of the confluence multi-way valve is not complex, and the control largely employs simple hydraulic control methods, resulting in low design costs and reliable confluence control.

[0023] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0025] Figure 1 This is a hydraulic schematic diagram of a merging multi-way valve according to one embodiment of this application;

[0026] Figure 2 for Figure 1 A partially enlarged schematic diagram of the merging control section;

[0027] Figure 3 Hydraulic schematic diagram of a merging multi-way valve according to another embodiment of this application;

[0028] Figure 4 for Figure 3 A partially enlarged schematic diagram of the merging control section.

[0029] Explanation of reference numerals in the attached figures

[0030] Detailed Implementation

[0031] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0032] The following description, with reference to the accompanying drawings, describes a merging multi-way valve and a dual-pump hydraulic system according to this application.

[0033] This application first discloses a confluence multi-way valve, such as Figure 1 As shown, in one specific embodiment, the merging multi-way valve includes:

[0034] The load-sensitive unit includes a first main working oil circuit L1 with a first pumping oil inlet P1 and multiple first working connections connected in parallel to the first main working oil circuit L1.

[0035] The bypass throttling unit includes a second main working oil passage L2 with a second pump inlet P2, and at least one second working connection is provided in the second main working oil passage L2.

[0036] The confluence control link 5 includes a confluence reversing valve 52 and a pressure relief valve 53. The confluence reversing valve 52 is used to switch the connection between the second main working oil circuit L2 and the first main working oil circuit L1, and the pressure relief valve 53 is used to control the return oil of the second main working oil circuit L2.

[0037] This application aims to design a novel confluence multi-way valve to achieve a confluence scheme between the load-sensitive oil circuits of the first pump (extension, luffing, and hoisting) and the bypass throttling system of the second pump. Functionally, the confluence multi-way valve may include a load-sensitive unit, a bypass throttling unit, and a confluence control linkage. Specifically, with... Figure 1 For example, the load-sensitive unit may further include a first pump oil inlet control link 1 and, as a first working link, such as a telescopic reversing link 2, a luffing reversing link 3, a hoisting reversing link 4, etc., and the bypass throttling unit may include a second pump oil inlet control link 7 and a slewing reversing link 6, etc., as a second working link.

[0038] In this system, the merging directional valve 52 in the merging control linkage 5 is used to switch the connection between the second main working oil circuit L2 and the first main working oil circuit L1. When the two pumping oil circuits are combined, dual-pump merging is achieved; conversely, when the two oil circuits are cut off, dual-pump merging is discontinued. In this embodiment, the merging directional valve 52 is a hydraulically controlled directional valve to achieve stable and reliable merging control. Of course, electromagnetic switching valves or other forms could also be used, but this would inevitably involve a more complex electronic control system and higher costs.

[0039] Specifically, the flow control unit 5 also employs a pressure-limiting unloading valve 53, which controls the return oil of the second main working oil circuit L2, thereby disengaging the dual-pump flow and achieving the unloading protection function. Specifically, through the pressure-limiting unloading valve 53, low-pressure dual-pump flow can be achieved for telescopic, luffing, and winching operations based on engine power, while switching to single-pump oil supply in high-pressure mode, improving working efficiency.

[0040] The second working connection includes a second actuating directional valve. The second main working oil circuit L2 passes through the second actuating directional valve and is configured to be in an oil circuit open state in the cut-off neutral position of the second actuating directional valve and in an oil circuit closed state in the working directional valve position. For example... Figure 1 , Figure 2As shown in the example, the second working link only performs a rotational action, i.e., it includes the rotation reversing link 6. The rotation reversing link 6 includes a rotation reversing valve 61 and an inlet check valve 62. The oil flows from the second pump inlet P2 into the second main working oil passage L2 of the confluence multi-way valve, passes through the inlet check valve 62, and flows into the inlet side of the rotation reversing valve 61. At the outlet side of the rotation reversing valve 61, the oil is split to the confluence reversing valve 52 and the pressure relief valve 53. Specifically, when the rotation reversing link 6 is in the closed neutral position, the second main working oil passage L2 is open; when the rotation reversing link 6 is in the working reversing valve position (i.e., the upper or lower position), the second main working oil passage L2 is closed.

[0041] The bypass throttling unit includes a second return port T2. The second main working oil circuit L2 is connected to the second return port T2 via a pressure relief valve 53, and is connected in parallel to the first main working oil circuit L1 via a merging directional valve 52. Therefore, when the slewing action is not performed, the second main working oil circuit L2 can merge with the first main working oil circuit L1 through the merging directional valve 52 via the cut-off neutral position of the slewing directional valve 6, or flow back to the second return port T2 via the pressure relief valve 53. However, once the second directional valve is in operation, i.e., when the slewing action is performed as shown in the figure, the pressure oil at the second pump inlet P2 can only be used for the slewing action and cannot be used for merging.

[0042] exist Figure 1 In the confluence control unit 5, an anti-backflow check valve 51 is included to prevent oil from flowing to the confluence directional valve 52. The anti-backflow check valve 51 is located in the first main working oil circuit L1 and at the valve front end of the confluence directional valve 52. When the confluence directional valve 52 is in the right position to open to the first return port T1, the anti-backflow check valve 51 can prevent pressurized oil from the first pump inlet P1 from returning through the first main working oil circuit L1.

[0043] As the name suggests, the load-sensitive unit includes a load feedback control oil circuit LS. Each first working link includes a first action directional valve and a pressure reducing valve 42. The first outlet C1 of each pressure reducing valve is connected to the load feedback control oil circuit LS (shown by the dotted line in the figure). The inlet of the pressure reducing valve 42 is connected to the first main working oil circuit L1 through the first action directional valve and is set to be in the oil circuit cut-off state when the first action directional valve is in the cut-off position and in the oil circuit open state when the working directional valve is in the working position.

[0044] by Figure 1 , Figure 2Taking the winch reversing coupling 4 as an example, the winch reversing coupling 4 includes a winch reversing valve 41 and a pressure reducing valve 42. The side branch oil passage of the first main working oil passage L1 leads to the left oil inlet side of the winch reversing valve 41, and further flows from the right oil outlet side of the winch reversing valve 41 to the inlet end of the pressure reducing valve 42, and at the same time flows to the upper control chamber of the pressure reducing valve 42. When the hoisting directional valve 41 is in the cut-off neutral position, the bypass oil circuit is obviously disconnected, and the pressure oil of the first main working oil circuit L1 cannot reach the pressure reducing valve 42 through the bypass oil circuit. However, as long as the hoisting directional valve 41 is switched to the working directional valve position (i.e., upper or lower position) under the control of the operating handle, the bypass oil circuit is opened. At the same time, after the pressure oil reaches the pressure reducing valve 42, the pressure reducing valve 42 can be switched to the upper position. Thus, most of the pressure oil of the first main working oil circuit L1 flows out from the second outlet C2 of the pressure reducing valve 42 through the bypass oil circuit, and then flows to the A3 or B3 oil port as the pressure oil of the working oil circuit of the hoisting mechanism. Another small part flows out from the first outlet C1 of the pressure reducing valve 42 as the oil of the load feedback control oil circuit LS.

[0045] exist Figure 1 , Figure 2 Specifically, the confluence directional valve 52 and the pressure relief valve 53 are hydraulically controlled directional valves, and the load feedback control oil circuit LS serves as a pilot control oil circuit connected to the respective control chambers of the confluence directional valve 52 and the pressure relief valve 53. See also Figure 2 The pressurized oil flowing from the first outlet C1 of the pressure reducing valve 42 is partially directed to the load feedback control oil circuit LS, and partially used to pilot control the confluence directional valve 52 and the pressure relief valve 53. The pressurized oil can switch the confluence directional valve 52 to the left position, thus achieving the confluence of the first and second main working oil circuits. Therefore, as long as the hoisting reversing coupling 4 is activated, i.e., the operating handle of the hoisting reversing valve 41 is manipulated, the confluence directional valve 52 can be automatically hydraulically activated. Furthermore, as mentioned earlier, if the slewing reversing coupling 6 is not activated, the hoisting reversing coupling 4 can be driven by two pumps.

[0046] The above explanation only uses the hoist reversing coupling 4 as an example. When other telescopic reversing couplings 2 and luffing reversing couplings 3 are controlled separately, their control processes and hydraulic flow directions are the same as those of the hoist reversing coupling 4, and will not be elaborated on here.

[0047] Clearly, as can be seen from the above, when one or more of the first working links in the load-sensitive unit are working, while the second working link of the bypass throttling unit is not working, the two pumps can be directly combined to drive one or more of the first working links to work. If one or more of the first working links are working and the second working link is also working, the two pumps obviously cannot be combined; the first pump can only drive the first working link to work, and the second pump can only drive the second working link to work.

[0048] Furthermore, when the merging reversing valve 52 is activated to achieve merging of the two pumps, if the pressure of the load feedback control oil circuit LS is greater than the set reversing pressure of the pressure relief valve 53, the pressure relief valve 53 can be driven to reverse and open. The pressure oil of the second main working oil circuit L2 is connected to the second return oil port T2 through the pressure relief valve 53, so that the merging of the two pumps is cut off, and one or more first working connections are driven by the first pump alone.

[0049] like Figure 3 , Figure 4 As shown, in another embodiment, with Figure 1 , Figure 2 The only difference is that the hydraulic control terminals of both the confluence reversing valve 52 and the pressure relief valve 53 are connected to the second outlet C2 of the pressure reducing valve 42 of the hoist reversing coupling 4, rather than... Figure 2 The first outlet end C1 is shown.

[0050] Thus, in Figure 3 , Figure 4 In this implementation, when the telescopic reversing coupling 2 and the luffing reversing coupling 3 operate individually or together (excluding the hoisting reversing coupling 4), the load feedback control oil circuit LS cannot drive the control confluence reversing valve 52 and the pressure relief valve 53, thus preventing dual-pump confluence. Therefore, the telescopic reversing coupling 2 and the luffing reversing coupling 3 can only be driven by a single pump; dual-pump confluence drive can only be achieved when only the hoisting reversing coupling 4 is working.

[0051] Specifically, see Figure 1 In the first pump inlet control unit 1 of the load-sensitive unit, a first return port T1 is also included. A no-load unloading oil circuit is connected between the first main working oil circuit L1 and the first return port T1. A three-way flow valve 15 is installed in the no-load unloading oil circuit. The two control chambers of the three-way flow valve 15 are respectively connected to the load feedback control oil circuit LS and the first main working oil circuit L1. Once one or more first working connections are working, the pressure oil in the load feedback control oil circuit LS will control the three-way flow valve 15 to close, that is, the no-load unloading oil circuit is cut off under normal working conditions. When all first working connections are not working, the pressure oil in the first main working oil circuit L1 will overcome the spring force to open the three-way flow valve 15, allowing the pressure oil in the first main working oil circuit L1 to unload towards the first return port T1 through the no-load unloading oil circuit, i.e., the no-load unloading mode.

[0052] In addition, an emergency unloading oil circuit is connected between the first main working oil circuit L1 and the first return oil port T1, and an unloading valve 13 is installed in the emergency unloading oil circuit. The emergency unloading oil circuit is used to unload the oil pump and can cut off the protection system in case of dangerous operation. The unloading valve 13 can be a common on / off valve, such as a solenoid switch valve, but considering that it is an emergency unloading and a large flow rate of return without delay is required, the unloading valve 13 adopts a cartridge valve structure, and the control oil circuit of the cartridge valve is equipped with a solenoid ball valve 12. By activating the solenoid ball valve 12, the on / off state of the unloading valve 13 and the emergency unloading oil circuit can be controlled to achieve emergency unloading.

[0053] Furthermore, as those skilled in the art will know, the first pump inlet control line 1 is also equipped with a first main relief valve 14, and the second pump inlet control line 7 is also equipped with a second main relief valve 71, serving as main relief valves to maintain the basic safety of the system and to automatically unload when the system pressure exceeds the upper limit. Similarly, the pressure-limiting relief valve 43 is used for loop safety control in a single-operation working circuit.

[0054] Based on the aforementioned confluence multi-way valve, this application also discloses a dual-pump hydraulic system, including the aforementioned confluence multi-way valve; a load-sensitive variable pump for supplying oil to the first pump inlet P1; and a gear pump for supplying oil to the second pump inlet P2. Compared to the dual variable pump configuration, the dual-pump hydraulic system of this application has a lower cost, but can achieve confluence control of the first pump load-sensitive circuit and the second pump bypass throttling circuit.

[0055] This dual-pump hydraulic system can be applied to truck-mounted cranes and small-to-medium tonnage truck cranes, and can also be extended to other engineering vehicles and sanitation vehicles.

[0056] The following is Figure 1 , Figure 2 Taking this as an example, we will specifically explain the working status of each hydraulic valve and oil circuit in the confluence multi-way valve under multiple operating conditions of the dual-pump hydraulic system.

[0057] I. No-load condition

[0058] When the solenoid ball valve 12 is de-energized and in the right position, the unloading valve 13 is in the working state. The oil in the first pump inlet P1 does not flow through the telescopic reversing coupling 2, the luffing reversing coupling 3, and the winch reversing coupling 4. That is to say, the telescopic reversing valve 21, the luffing reversing valve 31, and the winch reversing valve 41 are all in the middle position. The pressure reducing valve 42 has no oil pressure in both the upper and lower chambers and is in the lower position. Therefore, the oil of the first pump (i.e., the load-sensitive variable pump) is pumped to the first main working oil circuit L1. As long as the system pressure overcomes the spring force of the three-way flow valve 15, the three-way flow valve 15 can be opened through the control port of the three-way flow valve 15, thereby realizing no-load low-pressure unloading.

[0059] The oil from the second pump (i.e., the gear pump) passes through the first port of the directional valve 61, which is connected to the first port of the confluence directional valve 52. At this time, the confluence directional valve 52 is in the right position, and the first, second, and third ports of the confluence directional valve 52 are connected, thereby achieving low-pressure unloading.

[0060] II. Hoisting reversing coupling 4 operates independently

[0061] When the operator operates the winch reversing coupling 4 alone, the pump oil enters the upper or lower position of the winch reversing valve 41. Then, the high-pressure oil enters the upper chamber of the pressure reducing valve 42, causing the luffing pressure reducing valve 42 to move downwards. After a mid-position transition, it reaches the upper position, and the high-pressure oil enters the control oil circuit, thereby closing the three-way flow valve 15. Simultaneously, the oil passes through the upper position of the pressure reducing valve 42 and the winch reversing valve 41 into the working oil port A3 or B3, causing the winch to operate. The load feedback control oil circuit LS simultaneously pushes the confluence reversing valve 52 to switch to the left position, cutting off the oil path from the second pump to the second return oil port T2. The oil then merges with the first main working oil circuit L1 via the anti-backflow check valve 51, simultaneously supplying the winch with power. If the pressure in the load feedback control oil circuit LS exceeds the set pressure of the pressure-limiting unloading valve 53, the pressure-limiting unloading valve 53 opens, and the oil from the second pump flows through the pressure-limiting unloading valve 53 to the T1 and T2 return oil passages. At this time, the first pump is in a single-supply state.

[0062] When the safety switch or limit switch is triggered during operation and needs to be safely cut off, the solenoid ball valve 12 is energized, and the oil circuit is unloaded.

[0063] The process is the same when other telescopic reversing coupling 2 or luffing reversing coupling 3 is working alone.

[0064] III. Reversing coupling 6 operates independently.

[0065] When the operator operates the slewing reversing valve 6 alone, the oil from the second pump enters the upper or lower position of the slewing reversing valve 61, the first working port of the slewing reversing valve 61 is cut off, and the oil enters the valve core through the inlet check valve 62, entering the working port A4 or B4, causing the slewing action. At this time, the first pump returns oil through the three-way flow valve 15.

[0066] IV. Any two of the following can work simultaneously: telescopic reversing coupler 2, luffing reversing coupler 3, and hoisting reversing coupler 4.

[0067] When the operator manipulates the two reversing couplings, the oil from the first pump corresponds to the pressure reducing valve and enters the load feedback control oil circuit LS through the pressure reducing valve, thereby closing the three-way flow valve 15. At the same time, the oil enters the working oil port through the pressure reducing valve.

[0068] Simultaneously, the load feedback control oil circuit LS pushes the confluence reversing valve 52 to switch to the left position. The oil from the second pump is cut off from the oil passage to port T2 via the second main working oil circuit L2, and then merges with the first main working oil circuit L1 via the check valve 42, simultaneously supplying the hoisting operation. If the pressure in the load feedback control oil circuit LS exceeds the set pressure of the pressure relief valve 53, the pressure relief valve 53 opens, and the oil from the second pump flows through the pressure relief valve 53 to the T1 and T2 return oil passages. At this time, the first pump is in a state of independent oil supply.

[0069] The telescopic reversing coupling 2, the luffing reversing coupling 3, and the hoisting reversing coupling 4 operate simultaneously, and their principle is the same as that of two simultaneous operations.

[0070] When the safety switch or limit switch is triggered during operation and needs to be safely cut off, the solenoid ball valve 12 is energized, and the oil circuit is unloaded.

[0071] 5. Any one of the telescopic reversing coupler 2, luffing reversing coupler 3, or hoisting reversing coupler 4 can work simultaneously with the slewing reversing coupler 6.

[0072] When telescopic reversing coupling 2 and slewing reversing coupling 6 work simultaneously, slewing reversing coupling 6 is supplied with oil by the second pump alone, while because slewing reversing valve 61 switches to the upper or lower position, the passage to the confluence direction is cut off, and telescopic reversing coupling 2 is supplied with oil by the first pump alone.

[0073] The simultaneous operation of the luffing commutator 3 and the slewing commutator 6, or the simultaneous operation of the hoisting commutator 3 and the slewing commutator 6, is also the same.

[0074] In summary, this application achieves a combined flow scheme for the first pump's telescopic, luffing, and hoisting oil circuit load-sensitive system and the second pump's bypass throttling system. The pressure-limiting and unloading valve 53 can achieve low-pressure dual-pump combined flow for telescopic, luffing, and hoisting operations based on engine power, switching to single-pump oil supply in high-pressure conditions, thus improving working efficiency. The electromagnetic ball valve 12 and unloading valve 13 can achieve oil pump unloading and provide safety protection against dangerous actions. Figure 4 As shown, by adjusting the pressure relief valve 53 to control the oil circuit, it is possible to further realize single-pump oil supply for telescopic and variable amplitude operations, and dual-pump oil supply for winch operations.

[0075] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0076] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0078] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A confluence multi-way valve, characterized in that, The merging multi-way valve includes: The load-sensitive unit includes a first main working oil passage (L1) with a first pumping oil inlet (P1) and a plurality of first working connections connected in parallel to the first main working oil passage (L1); The bypass throttling unit includes a second main working oil circuit (L2) with a second pumping inlet (P2). The second main working oil circuit (L2) has at least one second working link. The second working link includes a second actuation directional valve. The second main working oil circuit (L2) passes through the second actuation directional valve and is configured to be in an oil circuit open state when the second actuation directional valve is in the cut-off position and in an oil circuit closed state when the working directional valve is in the working position. The confluence control link (5) includes a confluence reversing valve (52) and a pressure relief valve (53). The confluence reversing valve (52) is used to switch the connection between the second main working oil circuit (L2) and the first main working oil circuit (L1). The pressure relief valve (53) is used to control the return oil of the second main working oil circuit (L2). The load-sensitive unit includes a load feedback control oil circuit (LS), each of the first working links includes a first action reversing valve and a pressure reducing valve (42), the first outlet end (C1) of each of the pressure reducing valves (42) is connected to the load feedback control oil circuit (LS), and the inlet end of the pressure reducing valve (42) is connected to the first main working oil circuit (L1) through the first action reversing valve and is configured to be in the oil circuit cut-off state in the cut-off position of the first action reversing valve and in the oil circuit open state in the working reversing valve position; The merging directional valve (52) and the pressure relief valve (53) are hydraulically controlled directional valves. The load feedback control oil circuit (LS) is connected as a pilot control oil circuit to the control chambers of the merging directional valve (52) and the pressure relief valve (53) respectively.

2. The merging multi-way valve according to claim 1, characterized in that, The bypass throttling unit includes a second return port (T2), the second main working oil circuit (L2) is connected to the second return port (T2) through the pressure relief valve (53), and is connected in parallel to the first main working oil circuit (L1) through the merging reversing valve (52).

3. The confluence multi-way valve according to claim 2, characterized in that, The confluence control link (5) includes an anti-backflow check valve (51) for preventing oil from flowing to the confluence reversing valve (52). The anti-backflow check valve (51) is located in the first main working oil circuit (L1) and at the valve front end of the confluence reversing valve (52).

4. The merging multi-way valve according to claim 1, characterized in that, The merging directional valve (52) and the pressure relief valve (53) are hydraulically controlled directional valves, and their hydraulic control ends are both connected to the second outlet end (C2) of the pressure reducing valve (42).

5. The confluence multi-way valve according to claim 1, characterized in that, The load-sensitive unit includes a first return port (T1), and an unloaded oil circuit is connected between the first main working oil circuit (L1) and the first return port (T1). A three-way flow valve (15) is provided in the unloaded oil circuit. The two control chambers of the three-way flow valve (15) are respectively connected to the load feedback control oil circuit (LS) and the first main working oil circuit (L1).

6. The confluence multi-way valve according to claim 1, characterized in that, The load-sensitive unit includes a first return oil port (T1), and an emergency unloading oil circuit is connected between the first main working oil circuit (L1) and the first return oil port (T1). The emergency unloading oil circuit is equipped with an unloading valve (13).

7. The confluence multi-way valve according to claim 6, characterized in that, The unloading valve (13) is a cartridge valve, and the control oil circuit of the cartridge valve is equipped with an electromagnetic ball valve (12).

8. A dual-pump hydraulic system, characterized in that, The dual-pump hydraulic system includes: The merging multi-way valve according to any one of claims 1 to 7; A load-sensitive variable pump is used to supply oil to the inlet (P1) of the first pump; A gear pump is used to supply oil to the second pump inlet (P2).

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