Multi-way valve control system and method

Abstract

The application discloses a kind of multi-way valve control systems and methods, the multi-way valve control system includes first hydraulic cylinder, second hydraulic cylinder, third hydraulic cylinder, at least one working link, communication each working link inlet oil passage and communication each working link back oil oil passage, a working link main valve is connected with the rod cavity of first hydraulic cylinder by first working oil path, the rod cavity of first hydraulic cylinder is connected with the rod cavity of second hydraulic cylinder, the working link main valve is connected with the first oil port of first switch valve by second working oil path, first switch valve includes the second oil port connected with the inlet oil port of second switch valve, the third oil port connected with the rodless cavity of third hydraulic cylinder and the fourth oil port connected with back oil oil passage, second switch valve includes the first oil port connected with the rodless cavity of first hydraulic cylinder and the second oil port connected with the center passage of first hydraulic cylinder, the center passage of first hydraulic cylinder is connected with the rodless cavity of second hydraulic cylinder. Improve utilization, reduce cost, reduce fault point, improve system performance and reliability.

Description

Technical Field

[0001] This invention relates to multi-way valves, and more specifically, to a multi-way valve control system. Furthermore, it also relates to a multi-way valve control method. Background Technology The main operating actions of a truck crane include the main winch, auxiliary winch, luffing, telescopic, and slewing systems. The luffing system controls the raising and lowering of the boom by extending and retracting the luffing cylinder, while the telescopic system controls the extension and retraction of the boom by telescopic cylinders and telescopic mechanisms.

[0002] There are generally three control methods for truck cranes operating on the vehicle: manual, hydraulic, and electric. Currently, the main products on the market are hydraulic and electric, with hydraulic products accounting for the highest proportion.

[0003] When operating a hydraulically controlled truck crane, the left and right movements controlled by the right hydraulic control handle are for luffing and telescopic actions, meaning that the luffing and telescopic systems cannot actually operate simultaneously. However, for multi-way valves, the telescopic and luffing systems are controlled by independent multi-way valve linkages.

[0004] However, the main components of the amplitude-changing and telescopic linkages of multi-way valves are basically the same, resulting in component duplication and low utilization rate and high cost of multi-way valves. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a multi-way valve control system that can effectively improve utilization, reduce costs, reduce failure points, and improve system performance and reliability.

[0006] To address the aforementioned technical problems, the present invention provides a multi-way valve control system, comprising a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder, at least one working link, an inlet oil passage connecting each of the working links, and a return oil passage connecting each of the working links. A main valve of one of the working links is connected to the rod chamber of the first hydraulic cylinder via a first working oil passage. The rod chamber of the first hydraulic cylinder is connected to the rod chamber of the second hydraulic cylinder. The main valve of the working link is connected to a first port of a first switching valve via a second working oil passage. The first switching valve includes a second port connected to the inlet of the second switching valve, a third port connected to the rodless chamber of the third hydraulic cylinder, and a fourth port connected to the return oil passage. The second switching valve includes a first port connected to the rodless chamber of the first hydraulic cylinder and a second port connected to the central channel of the first hydraulic cylinder. The central channel of the first hydraulic cylinder is connected to the rodless chamber of the second hydraulic cylinder.

[0007] In some embodiments, the second switching valve includes a switching main valve and a switching control valve. The switching control valve is connected to the control chambers at both ends of the switching main valve. The switching main valve includes a first oil port connected to a first oil port of the second switching valve, a second oil port connected to a second oil port of the second switching valve, a third oil port, and a fourth oil port connected to the oil inlet of the second switching valve. The third oil port of the second switching valve is connected to the return oil circuit.

[0008] In some embodiments, a check valve is provided between the oil passage between the third port of the second switching valve and the switching control valve and the third port of the switching main valve to guide oil in one direction to the third port of the second switching valve; a check valve is provided between the oil passage between the third port of the second switching valve and the switching control valve and the second port of the switching main valve to guide oil in one direction to the second port of the switching main valve; and the first port of the second switching valve is connected to its third port.

[0009] In some embodiments, a first balance valve is installed in the oil line between the rodless chamber of the first hydraulic cylinder and the second switching valve, a second balance valve is installed in the oil line between the rodless chamber of the second hydraulic cylinder and the central channel of the first hydraulic cylinder, and a third balance valve is installed in the oil line between the rodless chamber of the third hydraulic cylinder and the first switching valve.

[0010] In some embodiments, the control end of the third balancing valve is connected to a balancing control valve.

[0011] In some embodiments, the system further includes an oil inlet line and a pilot oil circuit. The oil inlet line includes a pilot directional valve disposed on the pilot oil circuit, and the control terminal of the main valve of each working line is connected to the pilot oil circuit.

[0012] In some embodiments, the control end of the main valve of each working link is connected to a pilot control valve installed in the pilot oil line.

[0013] In some embodiments, an operating handle valve assembly is also included, wherein the pilot oil circuit is connected to the control terminal of the main valve of each of the working couplers via the operating handle valve assembly.

[0014] In some embodiments, the control terminal of the first switching valve is connected to a switching pilot valve.

[0015] In some embodiments, the first switching valve and the switching pilot valve are an integrated switching valve assembly.

[0016] In some embodiments, an overflow valve is provided between the second working oil circuit and the return oil circuit.

[0017] In some embodiments, the control terminal of the overflow valve is connected to an overflow control valve.

[0018] The technical problem to be solved by the present invention is to provide a multi-way valve control method, which can effectively improve utilization and enhance system performance and reliability.

[0019] Another aspect of the present invention provides a multi-way valve control method. Based on any one of the above technical solutions, the multi-way valve control system includes the following steps: When the first switching valve is in the upper position, the second working oil circuit of the main valve of the working link is connected to the second switching valve through the first switching valve; When the second switching valve is in the right position, the extension and retraction of the piston rod of the first hydraulic cylinder is controlled by the reversing of the main valve of the working link; when the second switching valve is in the left position, the extension and retraction of the piston rod of the second hydraulic cylinder is controlled by the reversing of the main valve of the working link. When the first switching valve is in the lower position, the second working oil circuit of the main valve of the working link is connected to the third hydraulic cylinder through the first switching valve. By switching the main valve of the working link, the extension and retraction of the piston rod of the third hydraulic cylinder is controlled.

[0020] The beneficial effects of the present invention through the above technical solution are as follows: The second switching valve can accommodate two telescopic cylinder products, enabling the switching of the operation between the first and second hydraulic cylinders. The first switching valve can switch between different functional systems, such as the luffing system and the telescopic system. Furthermore, the first, second, and third hydraulic cylinders share a common main valve in the working connection. While meeting the operational functions of the vehicle, this reduces the number of components in the multi-way valve, lowers the potential for failure, improves system performance and reliability, and significantly reduces the cost and weight of the multi-way valve.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a hydraulic schematic diagram of the multi-way valve control system in a specific embodiment of the present invention; Figure 2 This is a hydraulic schematic diagram of the multi-way valve in a specific embodiment of the present invention; Figure 3 This is a hydraulic schematic diagram illustrating the switching method between the three hydraulic cylinders in a specific embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures 1-Main pump; 2-Inlet valve; 3-Second hydraulic cylinder; 4-Second balance valve; 5-Third hydraulic cylinder; 6-Third balance valve; K1-Control port of the third balance valve; 7-Balance control valve; 8-Left handle; L1-First oil port of the left handle; L2-Second oil port of the left handle; L3-Third oil port of the left handle; L4-Fourth oil port of the left handle; 9-Right handle; R1-First oil port of the right handle; R2-Second oil port of the right handle; R3-Third oil port of the right handle; R4-Fourth oil port of the right handle; 10-Oil tank; 100-Inlet oil circuit; 101-Return oil circuit; 102-Pilot oil circuit; 21-First one-way damping valve; 22-First pilot control valve; 23-First relief valve; 24-Relief control valve; 25-Second relief valve; 2 6-First switching valve; 27-Switching pilot valve; 28-Pressure compensation valve; 29-Main valve; 210-Second pilot control valve; 211-Second one-way damping valve; 212-Pilot directional valve; A1-First port of telescopic linkage; B1-Second port of telescopic linkage; A2-First port of return linkage; B2-Second port of return linkage; T-Return port of return linkage; 201-First working oil circuit; 202-Second working oil circuit; 11-First hydraulic cylinder; 12-First balance valve; 13-Second switching valve; 131-Switching main valve; 132-Switching control valve; P-Inlet of second switching valve; A-First port of second switching valve; B-Second port of second switching valve; Y-Third port of second switching valve; K2-Control port of second switching valve; Detailed Implementation The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention, and the scope of protection of the present invention is not limited to the specific embodiments described below.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, the terms “first,” “second,” “third,” and “fourth” 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,” “second,” “third,” or “fourth” may explicitly or implicitly include one or more of the stated features.

[0026] First, it should be noted that the hydraulic system of the multi-way valve control system of this invention belongs to the field of hydraulics. For those skilled in the art, its essential technical concept lies in the hydraulic connection relationship. Related hydraulic components, such as directional valves, handles, relief valves, and check valves, are well-known to those skilled in the art and are commonly used components in existing hydraulic systems. Therefore, these hydraulic components will only be briefly described below. After understanding the technical concept of this invention, those skilled in the art can also make simple substitutions to the oil circuits or valves to achieve the function of the hydraulic system of the multi-way valve control system of this invention, which also falls within the scope of protection of this invention.

[0027] like Figures 1 to 3 As shown, the present invention provides a multi-way valve control system, including a first hydraulic cylinder 11, a second hydraulic cylinder 3, a third hydraulic cylinder 5, at least one working link, an oil inlet circuit 100, and an oil return circuit 101. The oil inlet circuit 100 connects to each working link, and the oil return circuit 101 connects to each working link. The main valve 29 of one working link is connected to the rod chamber of the first hydraulic cylinder 11 via the first working oil circuit 201. The rod chamber of the first hydraulic cylinder 11 is connected to the rod chamber of the second hydraulic cylinder 3. The main valve 29 of this working link is also connected to the first port of a first switching valve 26 via the second working oil circuit 202. 26 also includes a second oil port, a third oil port, and a fourth oil port. The second oil port of the first switching valve 26 is connected to the oil inlet P of the second switching valve 13. The third oil port of the first switching valve 26 is connected to the rodless chamber of the third hydraulic cylinder 5. The fourth oil port of the first switching valve 26 is connected to the return oil circuit 101. The second switching valve 13 includes a first oil port A and a second oil port B. The first oil port A of the second switching valve 13 is connected to the rodless chamber of the first hydraulic cylinder 11. The second oil port B of the second switching valve 13 is connected to the central channel of the first hydraulic cylinder 11. The central channel of the first hydraulic cylinder 11 is connected to the rodless chamber of the second hydraulic cylinder 3.

[0028] To facilitate the explanation of the technical solution of this invention, the following description mainly uses the first hydraulic cylinder 11 and the second hydraulic cylinder 3 as cylinders for the telescopic movement of the crane and the third hydraulic cylinder 5 as cylinders for the luffing movement of the crane as examples. The first hydraulic cylinder 11 and the second hydraulic cylinder 3 are formed as two telescopic cylinder products. It should be noted that the technical solution of this invention is not limited to the control of the telescopic movement and luffing movement of the crane, but can also be applied to other related movements. Moreover, it is not limited to cranes, but can be applied to other engineering machinery that needs to perform compound movements, such as excavators.

[0029] Controlling the first switching valve 26 to its upper position connects its first port to its second port and its third port to its fourth port. At this time, the main valve 29 of the working link connects to the inlet P of the second switching valve 13 via the second working oil passage 202. The third hydraulic cylinder 5 connects to the return oil passage 101 via the first switching valve 26, and the third hydraulic cylinder 5 does not operate, meaning the crane does not perform boom luffing operations. The inlet oil passage 100 supplies oil to the first hydraulic cylinder 11 and the second hydraulic cylinder 3 via the main valve 29 of this working link, thereby controlling the extension and retraction of the first hydraulic cylinder 11 and the second hydraulic cylinder 3, i.e., the crane performs boom extension and retraction operations. Specifically, controlling the second switching valve 13 connects its inlet P to its first port A. The connection is established because the first port A of the second switching valve 13 is connected to the rodless chamber of the first hydraulic cylinder 11. The inlet oil passage 100 supplies hydraulic oil to the rodless chamber of the first hydraulic cylinder 11 through the main valve 29, the first switching valve 26, and the second switching valve 13 of the working link. The hydraulic oil in the rod chamber of the first hydraulic cylinder 11 flows back to the return oil passage 101 through the first working oil passage 201 and the main valve 29 of the working link, thereby controlling the extension action of the first hydraulic cylinder 11. After the main valve 29 of the working link is switched, the inlet oil passage 100 supplies hydraulic oil to the rod chamber of the first hydraulic cylinder 11 through the main valve 29 and the first working oil passage 201 of the working link. At the same time, the hydraulic oil in the rodless chamber of the first hydraulic cylinder 11 flows back to the return oil passage 101 through the second switching valve 13, the first switching valve 26, and the main valve 29 of the working link, thereby controlling the retraction action of the first hydraulic cylinder 11. When the second switching valve 13 is switched so that its inlet P is connected to its second port B, the second port B of the second switching valve 13 is connected to the central channel of the first hydraulic cylinder 11, and the central channel of the first hydraulic cylinder 11 is connected to the rodless chamber of the second hydraulic cylinder 3. At this time, the oil inlet circuit 100 supplies hydraulic oil to the rodless chamber of the second hydraulic cylinder 3 through the main valve 29, the first switching valve 26, and the second switching valve 13 of the working connection. Since the rod chamber of the first hydraulic cylinder 11 is connected to the rod chamber of the second hydraulic cylinder 3, the hydraulic oil in the rod chamber of the second hydraulic cylinder 3 passes through the rod chamber of the first hydraulic cylinder 11 and the first working oil circuit 2 of the second switching valve 13. 01. The main valve 29 of the working link flows back to the return oil passage 101 to control the extension action of the second hydraulic cylinder 3. After the main valve 29 of the working link is reversed, the inlet oil passage 100 delivers hydraulic oil to the rod chamber of the second hydraulic cylinder 3 through the main valve 29 of the working link, the first working oil passage 201, and the rod chamber of the first hydraulic cylinder 11. At the same time, the hydraulic oil in the rodless chamber of the second hydraulic cylinder 3 flows back to the return oil passage 101 through the second switching valve 13, the first switching valve 26, and the main valve 29 of the working link to control the retraction action of the first hydraulic cylinder 11.In other words, by setting the second switching valve 13, the switching action between the first hydraulic cylinder 11 and the second hydraulic cylinder 3 in the two telescopic hydraulic cylinder products can be controlled. When the first switching valve 26 is reversed, the first switching valve 26 is in the lower position, and its first oil port is connected to its third oil port, i.e., the crane performs boom luffing operation. At this time, the second oil port and its fourth oil port of the first switching valve 26 are in the closed state, i.e., the crane does not perform boom extension operation. The oil inlet circuit 100 delivers hydraulic oil to the rodless chamber of the third hydraulic cylinder 5 through the main valve 29 of the working link and the second working oil circuit 202, realizing the control operation of the extension action of the third hydraulic cylinder 5. Similarly, when the main valve 29 of the working link is reversed, the control operation of the retraction action of the third hydraulic cylinder 5 can be realized. This invention is based on a two-cylinder telescopic system. It uses a second switching valve 13 to switch the action of the first hydraulic cylinder 11 and the second hydraulic cylinder 3, and a first switching valve 26 to switch the boom telescopic and boom luffing actions. This allows the control of boom telescopic and boom luffing to be controlled by the same working link, combining the telescopic link and luffing link in the prior art into one. It can simultaneously meet the action function and performance requirements of the luffing and telescopic systems, reduce the number of multi-way valve components, reduce failure points, improve system performance and reliability, and greatly reduce the cost and weight of the multi-way valve.

[0030] Among them, Figure 1 In the illustrated embodiment, the first switching valve 26 is a two-position four-way valve. It is understood that the first switching valve 26 could also be any other hydraulic valve capable of performing the same function, such as a two-position five-way valve, where one port can be blocked as a spare port, or two parallel switching valves could be used instead. Furthermore, the control terminal of the first switching valve 26 is connected to a switching pilot valve 27, which controls the switching action of the first switching valve 26. Preferably, the switching pilot valve 27 is a solenoid valve. Further, the first switching valve 26 and the switching pilot valve 27 can be connected to the multi-way valve as independent valves, or they can be integrated into a single valve to form an integrated switching valve group within the multi-way valve. Alternatively, to control the switching action of the first switching valve 26, it could also be a proportional solenoid valve, thus eliminating the need for a switching pilot valve 27 to control the first switching valve 26.

[0031] In some specific embodiments, such as Figure 3As shown, the second switching valve 13 includes a switching main valve 131 and a switching control valve 132. The switching control valve 132 is connected to the two control chambers of the switching main valve 131 respectively. The switching main valve 131 includes a first oil port, a second oil port, a third oil port and a fourth oil port. The first oil port of the switching main valve 131 is connected to the first oil port A of the second switching valve 13. The second oil port of the switching main valve 131 is connected to the second oil port B of the second switching valve 13. The third oil port of the switching main valve 131 is connected to the third oil port Y of the second switching valve 13. The fourth oil port of the switching main valve 131 is connected to the oil inlet P of the second switching valve 13. The third oil port Y of the second switching valve 13 is connected to the return oil circuit 101.

[0032] Furthermore, a check valve is provided between the oil passage between the third port Y of the second switching valve 13 and the switching control valve 132 and the third port of the switching main valve 131. This check valve can guide the oil in one direction to the third port Y of the second switching valve 13. A check valve is also provided between the oil passage between the third port Y of the second switching valve 13 and the switching control valve 132 and the second port of the switching main valve 131. This check valve guides the oil in one direction to the second port of the switching main valve 131. The first port A of the second switching valve 13 is connected to its third port Y. When the first hydraulic cylinder 11 extends, hydraulic oil enters the rodless chamber of the first hydraulic cylinder 11 through the first port A of the second switching valve 13. The hydraulic oil in the rod chamber of the first hydraulic cylinder 11 flows back to the return oil circuit 101 through the first working oil circuit 201. Since the rod chamber of the first hydraulic cylinder 11 is connected to the rod chamber of the second hydraulic cylinder 3, some of the hydraulic oil in the rod chamber of the second hydraulic cylinder 3 will also flow out, causing the hydraulic oil in the central channel of the first hydraulic cylinder 11 to flow into the rodless chamber of the second hydraulic cylinder 3. At this time, the hydraulic oil flowing out from the first port A of the second switching valve 13 will be diverted to the third port Y of the second switching valve 13 through the check valve to the second port B of the second switching valve 13, and then flow to the central channel of the first hydraulic cylinder 11. The central channel of the first hydraulic cylinder 11 is connected to the third port Y of the second switching valve 13 through the second port B of the second switching valve 13, and connected to the system return oil back pressure to ensure that the central channel of the first hydraulic cylinder 11 is not sucked dry.

[0033] In some specific embodiments, a first balance valve 12 is installed on the oil line between the rodless chamber of the first hydraulic cylinder 11 and the second switching valve 13, and the control end of the first balance valve 12 is connected to the oil inlet channel of the rod chamber of the first hydraulic cylinder 11; a second balance valve 4 is installed on the oil line between the rodless chamber of the second hydraulic cylinder 3 and the central channel of the first hydraulic cylinder 11, and the control end of the second balance valve 4 is connected to the oil inlet channel of the rod chamber of the second hydraulic cylinder 3; a third balance valve 6 is installed on the oil line between the rodless chamber of the third hydraulic cylinder 5 and the first switching valve 26, and the control port K1 of the third balance valve 6 is connected to the balance control valve 7, which can be a solenoid valve. Alternatively, the third balance valve 6 can be a proportional solenoid valve, eliminating the need for a balance control valve 7 to control the switching of the third balance valve 6.

[0034] In some specific embodiments, an oil inlet line 2 and a pilot oil passage 102 are also provided. The oil inlet oil passage 100 connects the oil inlet line 2 to each working line, and the oil return line 101 connects the oil inlet line 2 to each working line. A pilot directional valve 212 is provided in the oil inlet line 2. One port of the pilot directional valve 212 is connected to the oil tank 10, and the other port of the pilot directional valve 212 is connected to the control terminal of the main valve of each working line through the pilot oil passage 102, so as to provide pilot oil to the control terminal of the main valve of each working line. The pilot directional valve 212 can be a solenoid valve.

[0035] In some specific embodiments, an operating handle valve assembly is installed on the pilot oil circuit 102. The operating handle valve assembly controls the main valve of each working link, thereby realizing the switching of the main valve of the corresponding working link. A pilot control valve is provided between the operating handle valve assembly and the control end of the main valve of each working link. The pilot control valve can be a solenoid valve.

[0036] In some specific embodiments, taking the telescopic linkage as an example of the working link that controls the operation of the first hydraulic cylinder 11, the second hydraulic cylinder 3, and the third hydraulic cylinder 5, the working link includes a pressure compensation valve 28 and a main valve 29. The oil inlet circuit 100 is connected to the main valve 29 through the pressure compensation valve 28. The pressure compensation valve 28 is connected to the first working oil circuit 201 and the second working oil circuit 202 through the main valve 29, respectively, to control the pressure difference between the oil inlet and outlet of the main valve 29, so as to realize the function that the flow rate through the main valve 29 is only related to the valve opening of the main valve 29. One end of the main valve 29 is connected to the first pilot control valve 22 and the first one-way damping valve 21 in sequence. The other end of the main valve 29 is connected to the second pilot control valve 210 and the second one-way damping valve 211 in sequence. A first relief valve 23 is provided between the first working oil circuit 201 and the return oil circuit. A second relief valve 25 is provided between the second working oil circuit 202 and the return oil circuit. The control chamber of the second relief valve 25 is connected to the relief control valve 24. The relief control valve 24 can be a solenoid valve. The relief control valve 24 is connected to the oil tank 10 and to one of the ports of the pilot directional valve 212.

[0037] In some specific embodiments, other working connections are structurally similar to the aforementioned telescopic connection, also including a pressure compensation valve 28 and a main valve 29. The oil inlet circuit 100 is connected to the main valve 29 via the pressure compensation valve 28. The pressure compensation valve 28 is connected to two working oil circuits via the main valve 29, and these two working oil circuits are respectively connected to an actuator to drive the actuator. The actuator can be a hydraulic cylinder, hydraulic motor, etc., to control the pressure difference between the oil inlet and outlet of the main valve 29, achieving the function that the flow rate through the main valve 29 is only related to the valve opening degree of the main valve 29. Of course, other working connections may also differ structurally from the aforementioned telescopic connection. Furthermore, each working link's main valve 29 has a load feedback port, which is used to feedback the load pressure of the corresponding load in each working link. The load feedback ports of each working link's main valve 29 are connected by shuttle valves, forming a network design for filtering load pressure. The load pressure is fed back to the main pump 1 through a shuttle valve to control the output flow of the main pump 1. The main pump 1 is preferably a variable displacement pump. A portion of the hydraulic oil output by the main pump 1 is output to the system's pilot oil circuit 102 through the pressure reducing valve and pilot directional valve 212 in the inlet link 2, for the control of the main valve 29 of each working link. Of course, the control oil source can also be output in other forms. Specifically, a separate hydraulic pump can be set up to control the output of the oil source, such as a rotary pump or gear pump.

[0038] In some specific embodiments, such as Figure 1As shown, the operating handle valve assembly can consist of a left handle 8 and a right handle 9. The left handle 8 has a first oil port L1, a second oil port L2, a third oil port L3, and a fourth oil port L4, while the right handle 9 has a first oil port R1, a second oil port R2, a third oil port R3, and a fourth oil port R4. In one specific embodiment, the first oil port L1 and the third oil port L3 of the left handle 8 can be connected to both ends of the main valve 29 within the rotary coupling, respectively, to control the rotary motion. Specifically, when the left handle 8 is moved to the left, pilot oil can flow through the third oil port L3 of the left handle 8 to the control end of one end of the main valve 29 within the rotary coupling; when the left handle 8 is moved to the right, pilot oil can flow through the first oil port L1 of the left handle 8 to the control end of the other end of the main valve 29 within the rotary coupling. The second oil port L2 and the fourth oil port L4 of the left handle 8 can be connected to both ends of the main valve 29 in the auxiliary hoisting assembly, respectively, to control the operation of the auxiliary hoist. Specifically, when the left handle 8 is moved forward, the pilot oil can flow through the fourth oil port L4 of the left handle 8 to the control end of one end of the main valve 29 in the auxiliary hoisting assembly. When the left handle 8 is moved backward, the pilot oil can flow through the second oil port L2 of the left handle 8 to the control end of the other end of the main valve 29 in the auxiliary hoisting assembly. Similarly, as a specific embodiment, the first oil port R1 and the third oil port R3 of the right handle 9 can be connected to the control terminals at both ends of the main valve 29 in the telescopic linkage, respectively, to control the boom telescopic or luffing action. Specifically, the first oil port R1 of the right handle 9 is connected to the second one-way damping valve 211, and the third oil port R3 of the right handle 9 is connected to the first one-way damping valve 21. When the right handle 9 is moved to the left, the pilot oil can flow through the first oil port R1 of the right handle 9 to the second pilot control valve 210 at one end of the main valve 29 in the telescopic linkage. When the right handle 9 is moved to the right, the pilot oil can flow through the third oil port R3 of the right handle 9 to the first pilot control valve 22 at the other end of the main valve 29 in the telescopic linkage. Furthermore, the third oil port R3 of the right handle 9 is also connected to the oil inlet of the balance control valve 7, and the return oil ports of the pilot valve 27, the balance control valve 7, the left handle 8, and the right handle 9 are interconnected, and are connected to the oil tank 10 through the same oil circuit as the overflow control valve 24. The second oil port R2 and the fourth oil port R4 of the right handle 9 can be connected to both ends of the main valve 29 in the main hoisting linkage, respectively, to control the main hoisting action. Specifically, when the right handle 9 is moved forward, the pilot oil can flow through the fourth oil port R4 of the right handle 9 to the control end of one end of the main valve 29 in the main hoisting linkage. When the right handle 9 is moved backward, the pilot oil can flow through the second oil port R2 of the right handle 9 to the control end of the other end of the main valve 29 in the main hoisting linkage.

[0039] Based on the above-described technical solution for a multi-way valve control system, the present invention also provides a multi-way valve control method, comprising the following steps: When the first switching valve 26 is in the upper position, the second working oil circuit 202 of the main valve of the working link is connected to the second switching valve 13 through the first switching valve 26. The switching of the first switching valve 26 can switch between telescopic and luffing actions. In one specific embodiment, the first switching valve 26 is switched to the upper position, at which time the first switching valve 26 is connected to the second switching valve 13 and can be used to control the telescopic action.

[0040] When the second switching valve 13 is in the right position, the extension and retraction of the piston rod of the first hydraulic cylinder 11 is controlled by switching the main valve of the working link; when the second switching valve 13 is in the left position, the extension and retraction of the piston rod of the second hydraulic cylinder 3 is controlled by switching the main valve 29 of the working link. The switching of the second switching valve 13 allows for the switching between the first hydraulic cylinder 11 and the second hydraulic cylinder 3 in the two telescopic cylinder products. In one specific embodiment, switching the second switching valve 13 to the left position controls the extension and retraction of the piston rod of the second hydraulic cylinder 3 by switching the main valve 29 of the working link. When switching the second switching valve 13 to the right position controls the extension and retraction of the piston rod of the first hydraulic cylinder 11 by switching the main valve 29 of the working link.

[0041] When the first switching valve 26 is in the lower position, the second working oil circuit 202 of the main valve of the working link is connected to the third hydraulic cylinder 5 through the first switching valve 26. By switching the main valve of the working link, the extension and retraction of the piston rod of the third hydraulic cylinder 5 is controlled. In a specific embodiment, the first switching valve 26 is switched to the lower position function. At this time, the first switching valve 26 is connected to the third hydraulic cylinder 5 and can be used for controlling the luffing action.

[0042] It is understandable that in the above technical solution, the specific operation sequence is not limited to the above operation steps. That is to say, the above steps do not have strict order requirements. The order of each step can be adapted and changed according to the actual operation needs to achieve different functions.

[0043] To better understand the technical concept of this invention, a relatively comprehensive description is provided below.

[0044] like Figures 1 to 3As shown, a preferred embodiment of the present invention provides a multi-way valve control system, including a first hydraulic cylinder 11, a second hydraulic cylinder 3, a third hydraulic cylinder 5, at least one working link, an oil inlet link 2, an operating handle valve group, an oil inlet circuit 100, and an oil return circuit 101. The description will be based on the example of the first hydraulic cylinder 11 and the second hydraulic cylinder 3 being used for the extension and retraction of the crane, and the third hydraulic cylinder 5 being used for the luffing action of the crane. The oil inlet circuit 100 connects the oil inlet link 2 to each working link, and the oil return circuit 101 connects the oil inlet link 2 to each working link. One of the working links is a telescopic link, which includes a pressure compensation valve 28 and a main valve 29. The oil inlet circuit 100 is connected to the main valve 29 via the pressure compensation valve 28. The pressure compensation valve 28 is connected to the first working oil circuit 201 and the second working oil circuit 202 via the main valve 29, respectively, to control the pressure difference between the oil inlet and outlet of the main valve 29. This ensures that the flow rate through the main valve 29 is only related to the valve opening of the main valve 29. The control chamber at one end is sequentially connected to the first pilot control valve 22 and the first one-way damping valve 21. The control chamber at the other end of the main valve 29 is sequentially connected to the second pilot control valve 210 and the second one-way damping valve 211. A first relief valve 23 is provided between the first working oil circuit 201 and the return oil circuit. A second relief valve 25 is provided between the second working oil circuit 202 and the return oil circuit. The control chamber of the second relief valve 25 is connected to the relief control valve 24. The relief control valve 24 can be a solenoid valve. The relief control valve 24 is connected to the oil tank 10 and to one port of the pilot directional valve 212. The main valve 29 of the working link is connected to the rod chamber of the first hydraulic cylinder 11 through the first working oil passage 201. The rod chamber of the first hydraulic cylinder 11 is connected to the rod chamber of the second hydraulic cylinder 3. The main valve 29 of the working link is also connected to the first port of the first switching valve 26 through the second working oil passage 202. The second port of the first switching valve 26 is connected to the inlet P of the second switching valve 13. The third port of the first switching valve 26 is connected to the rodless chamber of the third hydraulic cylinder 5. The fourth port of the first switching valve 26 is connected to the return oil passage 101. The control end of the first switching valve 26 is equipped with a switching pilot valve 27, which is used to control the switching of the first switching valve 26.The second switching valve 13 includes a switching main valve 131 and a switching control valve 132. The switching control valve 132 is connected to the control chambers at both ends of the switching main valve 131. The first oil port of the switching main valve 131 is connected to the first oil port A of the second switching valve 13. The second oil port of the switching main valve 131 is connected to the second oil port B of the second switching valve 13. The third oil port of the switching main valve 131 is connected to the third oil port Y of the second switching valve 13. The fourth oil port of the switching main valve 131 is connected to the inlet P of the second switching valve 13. The third oil port Y of the second switching valve 13 is connected to the return oil port. Oil circuit 101 is connected. A check valve is installed between the oil circuit between the third port Y of the second switching valve 13 and the switching control valve 132 and the third port of the switching main valve 131. This check valve can guide the oil in one direction to the third port Y of the second switching valve 13. A check valve is also installed between the oil circuit between the third port Y of the second switching valve 13 and the switching control valve 132 and the second port of the switching main valve 131. This check valve guides the oil in one direction to the second port of the switching main valve 131. The first port A of the second switching valve 13 is connected to its third port Y. The first port A of the second switching valve 13 is connected to the rodless chamber of the first hydraulic cylinder 11. The second port B of the second switching valve 13 is connected to the central channel of the first hydraulic cylinder 11. The central channel of the first hydraulic cylinder 11 is connected to the rodless chamber of the second hydraulic cylinder 13. A first balance valve 12 is installed on the oil line between the rodless chamber of the first hydraulic cylinder 11 and the second switching valve 13. The control end of the first balance valve 12 is connected to the oil inlet channel of the rod chamber of the first hydraulic cylinder 11. A second balance valve 4 is installed on the oil line between the rodless chamber of the second hydraulic cylinder 3 and the center channel of the first hydraulic cylinder 11. The control end of the second balance valve 4 is connected to the oil inlet channel of the rod chamber of the second hydraulic cylinder 3. A third balance valve 6 is installed on the oil line between the rodless chamber of the third hydraulic cylinder 5 and the first switching valve 26. The control port K1 of the third balance valve 6 is connected to the balance control valve 7, which can be a solenoid valve. The operating handle valve group consists of a left handle 8 and a right handle 9. The left handle 8 has a first oil port L1, a second oil port L2, a third oil port L3, and a fourth oil port L4. The right handle 9 has a first oil port R1, a second oil port R2, a third oil port R3, and a fourth oil port R4. The first oil port R1 of the right handle 9 is connected to the second one-way damping valve 211, the third oil port R3 of the right handle 9 is connected to the first one-way damping valve 21, and the third oil port R3 of the right handle 9 is also connected to the oil inlet of the balance control valve 7. The return oil port of the switching pilot valve 27, the return oil port of the balance control valve 7, the return oil port of the left handle 8 and the return oil port of the right handle 9 are interconnected, and are connected to the oil tank 10 through the same oil circuit as the overflow control valve 24.

[0045] The operation method of the multi-way valve control system of the present invention is as follows: 1. The first hydraulic cylinder 11 extends. The second pilot control valve 210 and pilot directional valve 212 are energized, while the first pilot control valve 22, switching pilot valve 27, balance control valve 7, relief control valve 24, and switching control valve 132 are de-energized. The de-energization of switching pilot valve 27 puts the first switching valve 26 in the upper position; the de-energization of balance control valve 7 connects the control port K1 of the third balance valve 6 to the system drain circuit, preventing the luffing action; the de-energization of relief control valve 24 makes the second relief valve 25 functional. The de-energization of the first pilot control valve 22 directly connects the upper control port of the main valve 29 to the system drain circuit; the de-energization of switching control valve 132 connects the inlet P of the second switching valve 13 to the first port A. After the pilot directional valve 212 is energized, it outputs pilot oil into the operating handle valve group. The right handle 9 controls the main valve 29 to switch, and the main pump 1 outputs high-pressure oil, which enters the oil inlet circuit 100. The oil then passes through the inlet P of the first switching valve 26 and the second switching valve 13 to its first oil port A, and through the first balance valve 12 into the rodless chamber of the first hydraulic cylinder 11, thus extending the first hydraulic cylinder 11. The return oil from the rod chamber of the first hydraulic cylinder 11 flows through the first oil port A1 of the telescopic connector, the first working oil circuit 201, and the main valve 29 to the return oil circuit 101. The second oil port B1 of the telescopic link and the second oil port B2 of the return link are connected through the first switching valve 26. By setting the second overflow valve 25, the system pressure is prevented from being too high when the arm is extended and the limitation on the extension of the arm under load is avoided. When the first hydraulic cylinder 11 is extended, the central channel of the first hydraulic cylinder 11 is connected to its third oil port Y through the second oil port B of the second switching valve 13, and connected to the system return oil back pressure to ensure that the central channel of the first hydraulic cylinder 11 is not sucked into the air.

[0046] 2. The first hydraulic cylinder 11 retracts. The first pilot control valve 22 and pilot directional valve 212 are energized, while the second pilot control valve 210, switching pilot valve 27, balance control valve 7, relief control valve 24, and switching control valve 132 are de-energized. The de-energization of switching pilot valve 27 puts the first switching valve 26 in the upper position; the de-energization of balance control valve 7 connects the control port K1 of the third balance valve 6 to the system drain circuit, preventing the luffing action; the de-energization of relief control valve 24 makes the second relief valve 25 functional. The de-energization of switching control valve 132 connects the inlet P of the second switching valve 13 to the first port A. After the pilot directional valve 212 is energized, pilot oil is output into the operating handle valve group, where the right handle 9 controls the main valve 29 to switch direction. The main pump 1 outputs high-pressure oil, which enters the inlet oil circuit 100 and flows through the first working oil circuit 201 into the rod chamber of the first hydraulic cylinder 11, opening the first balance valve 12 and retracting the first hydraulic cylinder 11. The return oil from the rodless chamber of the first hydraulic cylinder 11 flows through the first port A of the second switching valve 13 to its inlet port P, then through the second port B2 of the return oil connection, and finally back to the hydraulic oil tank. The first oil valve A1 of the telescopic connection is equipped with a first relief valve 23 to prevent excessive system pressure during boom retraction and to limit boom retraction under load. When the first hydraulic cylinder 11 retracts, its central channel connects to its third port Y through the second port B of the second switching valve 13, and then connects to the system's return oil back pressure chamber, ensuring that the central channel of the first hydraulic cylinder 11 does not experience pressure buildup.

[0047] 3. The second hydraulic cylinder 3 extends. The second pilot control valve 210, pilot directional valve 212, and switching control valve 132 are energized, while the first pilot control valve 22, switching pilot valve 27, balance control valve 7, and relief control valve 24 are de-energized. The de-energization of switching pilot valve 27 puts the first switching valve 26 in the upper position; the de-energization of balance control valve 7 connects the control port K1 of the third balance valve 6 to the system drain circuit, preventing the luffing action; the de-energization of relief control valve 24 makes the second relief valve 25 functional. The de-energization of the first pilot control valve 22 directly connects the upper control port of the main valve 29 to the system drain circuit. The de-energization of switching control valve 132 connects the inlet P of the second switching valve 13 to the first port A. After the pilot directional valve 212 is energized, it outputs pilot oil into the operating handle valve group. The right handle 9 controls the main valve 29 to switch, and the main pump 1 outputs high-pressure oil, which enters the oil inlet circuit 100. The oil flows through the inlet P of the first switching valve 26 and the second switching valve 13 to its second port B, the central channel of the first hydraulic cylinder 11, and the second balance valve 4 into the rodless chamber of the second hydraulic cylinder 3, thus extending the second hydraulic cylinder 3. The return oil from the rod chamber of the second hydraulic cylinder 3 returns to the hydraulic oil tank through the rod chamber of the first hydraulic cylinder 11 and the first port A1 of the telescopic coupling. The second port B1 of the telescopic coupling and the second port B2 of the return coupling are connected by the first switching valve 26. By setting the second relief valve 25, the system pressure is prevented from being too high during boom extension and the extension of the boom under load is restricted. When the second hydraulic cylinder 3 extends, the first hydraulic cylinder 11 does not work.

[0048] 4. The second hydraulic cylinder 3 retracts. The first pilot control valve 22, pilot directional valve 212, and switching control valve 132 are energized, while the second pilot control valve 210, switching pilot valve 27, balance control valve 7, and relief control valve 24 are de-energized. The de-energization of switching pilot valve 27 puts the first switching valve 26 in the upper position; the de-energization of balance control valve 7 connects the control port K1 of the third balance valve 6 to the system's oil drain circuit, preventing the luffing action; the de-energization of relief control valve 24 enables the second relief valve 25 to function. The energization of switching control valve 132 connects the oil inlet P of the second switching valve 13 to the second oil port B. After the pilot directional valve 212 is energized, it outputs pilot oil into the operating handle valve group. The right handle 9 controls the main valve 29 to switch directions, and the main pump 1 outputs high-pressure oil, which enters the inlet oil circuit 100. The oil flows through the first working oil circuit 201 and the rod chamber of the first hydraulic cylinder 11 into the rod chamber of the second hydraulic cylinder 3, opening the second balance valve 4 and retracting the second hydraulic cylinder 3. The return oil from the rodless chamber of the second hydraulic cylinder 3 flows through the second balance valve 4, the second port B of the second switching valve 13 to its inlet port P, the second port B2 of the return oil connection, and then back to the hydraulic oil tank. The first oil A1 of the telescopic connection is equipped with a first relief valve 23 to prevent excessive system pressure during boom retraction and to limit boom retraction under load. When the second hydraulic cylinder 3 extends, the first hydraulic cylinder 11 does not operate.

[0049] 5. The third hydraulic cylinder 5 extends. The second pilot control valve 210, switching pilot valve 27, pilot directional valve 212, and balance control valve 7 are energized, while the first pilot control valve 22 and relief control valve 24 are de-energized. When switching pilot valve 27 is energized, the first switching valve 26 is in the lower position; when balance control valve 7 is energized, the right handle 9 outputs control oil to open the third balance valve 6, enabling the luffing action; when relief control valve 24 is de-energized, the second relief valve 25 functions effectively. When the first pilot control valve 22 is de-energized, the upper control port of the main valve 29 is directly connected to the system drain circuit. After pilot directional valve 212 is energized, it outputs pilot oil into the operating handle valve group, which controls the main valve 29 to switch direction by the right handle 9. The main pump 1 outputs high-pressure oil, which enters the inlet oil circuit 100, flows through the first switching valve 26, the first oil port A2 of the return oil connection, and the third balance valve 6 into the rodless chamber of the third hydraulic cylinder 5, enabling the extension of the third hydraulic cylinder 5. The rod chamber of the third hydraulic cylinder 5 is connected to the return port T, directly returning oil to the hydraulic oil tank. The first oil port A2 of the return oil connection and the second oil port B1 of the telescopic connection are connected through the lower position of the first switching valve 26. The second oil port B1 of the telescopic connection is equipped with a second relief valve 25 to prevent the system pressure from being too high when the boom is raised.

[0050] 6. The third hydraulic cylinder 5 retracts. When the switching pilot valve 27, pilot directional valve 212, balance control valve 7, and relief control valve 24 are energized, the second pilot control valve 210 and the first pilot control valve 22 are de-energized. Energizing the switching pilot valve 27 puts the first switching valve 26 in the lower position; the Y11 solenoid valve and balance control valve 7 are energized, and the right handle 9 outputs control oil to open the third balance valve 6 to achieve the luffing action. The relief control valve 24 is energized, and the second relief valve 25 is unloaded. Because the main valve 29 is in the neutral position during the luffing action and does not flow with hydraulic oil, the second pilot control valve 210 and the first pilot control valve 22 are de-energized, and the control ports at both ends of the main valve 29 directly drain oil from the system. After the pilot directional valve 212 is energized, it outputs pilot oil into the operating handle valve group. The right handle 9 controls the main valve 29 to switch directions. The third port R3 of the right handle 9 outputs pilot oil, which, through the balance control valve 7, opens the third balance valve 6. The return oil from the rodless chamber of the third hydraulic cylinder 5 returns to the hydraulic oil tank through the first port A2 of the return oil connection, the first switching valve 26, and the second relief valve 25. When the second pilot control valve 210 and the first pilot control valve 22 are de-energized, the main valve 29 has no displacement, and during luffing, the inlet oil circuit 100 has no output.

[0051] In crane overhead operation, the left and right directions of the right handle are generally used to switch between luffing and telescopic movements. This means the luffing and telescopic systems cannot operate simultaneously. However, a multi-way valve has independent luffing and telescopic linkages. This invention is based on the idea that luffing and telescopic movements cannot occur simultaneously during crane overhead operation, and that both luffing and telescopic actuators are hydraulic cylinders with essentially the same control principle. Based on the fact that a product with two telescopic hydraulic cylinders has a second switching valve 13 for both cylinders, by optimizing the control of the multi-way valve and the hydraulic system, the luffing and telescopic linkages of the multi-way valve can be combined into one, sharing the telescopic linkage of the multi-way valve in the two telescopic hydraulic cylinder products. While meeting the crane overhead operation function requirements, this significantly reduces the cost and weight of the multi-way valve, decreases the number of multi-way valve components, reduces potential failure points, and improves system performance and reliability.

[0052] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0053] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0054] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A multi-way valve control system, characterized in that, The system includes a first hydraulic cylinder (11), a second hydraulic cylinder (3), a third hydraulic cylinder (5), at least one working link, an oil inlet passage (100) connecting each of the working links, and an oil return passage (101) connecting each of the working links. The main valve of one working link is connected to the rod chamber of the first hydraulic cylinder (11) through the first working oil passage (201), and the rod chamber of the first hydraulic cylinder (11) is connected to the rod chamber of the second hydraulic cylinder (3). The main valve of the working link is connected to the first port of the first switching valve (26) through the second working oil passage (202). The first switching valve (26) includes a second oil port connected to the oil inlet (P) of the second switching valve (13), a third oil port connected to the rodless chamber of the third hydraulic cylinder (5), and a fourth oil port connected to the return oil circuit (101). The second switching valve (13) includes a first oil port (A) connected to the rodless chamber of the first hydraulic cylinder (11) and a second oil port (B) connected to the central channel of the first hydraulic cylinder (11). The central channel of the first hydraulic cylinder (11) is connected to the rodless chamber of the second hydraulic cylinder (3). The rod chamber of the third hydraulic cylinder (5) is connected to the hydraulic oil tank. A second relief valve (25) is provided between the second working oil circuit (202) and the return oil circuit (101). The control end of the second relief valve (25) is connected to the relief control valve (24). The first switching valve (26) is configured as follows: When the first switching valve (26) is in the upper position, the first oil port of the first switching valve (26) is connected to the second oil port, and the third oil port of the first switching valve (26) is connected to the fourth oil port. When the first switching valve (26) is in the lower position, the first oil port of the first switching valve (26) is connected to the third oil port; The overflow control valve (24) is configured as follows: When the third hydraulic cylinder (5) retracts, the overflow control valve (24) is energized so that the second overflow valve (25) is unloaded.

2. The multi-way valve control system according to claim 1, characterized in that, The second switching valve (13) includes a switching main valve (131) and a switching control valve (132). The switching control valve (132) is connected to the control chambers at both ends of the switching main valve (131). The switching main valve (131) includes a first oil port connected to the first oil port (A) of the second switching valve (13), a second oil port connected to the second oil port (B) of the second switching valve (13), a third oil port, and a fourth oil port connected to the oil inlet (P) of the second switching valve (13). The third oil port (Y) of the second switching valve (13) is connected to the return oil circuit (101).

3. The multi-way valve control system according to claim 2, characterized in that, A check valve is provided between the oil passage between the third port (Y) of the second switching valve (13) and the switching control valve (132) and the third port of the switching main valve (131) to guide the oil in one direction to the third port (Y) of the second switching valve (13). A check valve is provided between the oil passage between the third port (Y) of the second switching valve (13) and the switching control valve (132) and the second port of the switching main valve (131) to guide the oil in one direction to the second port of the switching main valve (131). The first port (A) of the second switching valve (13) is connected to its third port (Y).

4. The multi-way valve control system according to claim 2, characterized in that, A first balance valve (12) is installed on the oil line between the rodless chamber of the first hydraulic cylinder (11) and the second switching valve (13), a second balance valve (4) is installed on the oil line between the rodless chamber of the second hydraulic cylinder (3) and the central channel of the first hydraulic cylinder (11), and a third balance valve (6) is installed on the oil line between the rodless chamber of the third hydraulic cylinder (5) and the first switching valve (26).

5. The multi-way valve control system according to claim 4, characterized in that, The control end of the third balancing valve (6) is connected to a balancing control valve (7).

6. The multi-way valve control system according to any one of claims 1 to 5, characterized in that, It also includes an oil inlet line (2) and a pilot oil line (102). The oil inlet line (2) includes a pilot directional valve (212) installed on the pilot oil line (102). The control end of the main valve of each working line is connected to the pilot oil line (102).

7. The multi-way valve control system according to claim 6, characterized in that, The control end of the main valve of each working link is connected to a pilot control valve installed on the pilot oil circuit (102).

8. The multi-way valve control system according to claim 6, characterized in that, It also includes an operating handle valve assembly, wherein the pilot oil circuit (102) is connected to the control end of the main valve of each of the working links through the operating handle valve assembly.

9. The multi-way valve control system according to any one of claims 1 to 5, characterized in that, The control end of the first switching valve (26) is connected to a switching pilot valve (27).

10. The multi-way valve control system according to claim 9, characterized in that, The first switching valve (26) and the switching pilot valve (27) are an integrated switching valve assembly.

11. A multi-way valve control method, characterized in that, Based on the multi-way valve control system according to any one of claims 1 to 10, the control method includes the following steps: When the first switching valve (26) is in the upper position, the second working oil circuit (202) of the main valve of the working link is connected to the second switching valve (13) through the first switching valve (26); When the second switching valve (13) is in the right position, the extension and retraction of the piston rod of the first hydraulic cylinder (11) is controlled by the reversal of the main valve of the working link; when the second switching valve (13) is in the left position, the extension and retraction of the piston rod of the second hydraulic cylinder (3) is controlled by the reversal of the main valve of the working link. When the first switching valve (26) is in the lower position, the second working oil circuit (202) of the main valve of the working link is connected to the third hydraulic cylinder (5) through the first switching valve (26), and the extension and retraction of the piston rod of the third hydraulic cylinder (5) is controlled by the reversal of the main valve of the working link.

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