Multi-way valve and working machine

Abstract

This application discloses a multi-way valve and a working machine. The multi-way valve includes a valve body and a load-sensing circuit and a constant pressure output and mode switching circuit integrated on the valve body. A first load feedback oil circuit is provided inside the valve body. The load-sensing circuit includes a first oil inlet, a second load feedback oil port, and a second load feedback oil circuit. The constant pressure output and mode switching circuit includes a second oil inlet, a third load feedback oil port, and a constant pressure output oil port. In load-sensing mode, the oil circuits of the third load feedback oil port and the second load feedback oil port are connected, while the second oil inlet and the third load feedback oil port are disconnected. In constant pressure mode, the oil circuits of the third load feedback oil port and the second load feedback oil port are disconnected, while the oil circuits of the third load feedback oil port, the second oil inlet, and the constant pressure output oil port are connected. This application integrates the load-sensing function and the constant pressure function into a single valve body, reducing installation space, saving piping, and reducing costs.

Description

Technical Field

[0001] This application belongs to the field of operating machinery technology, specifically relating to a multi-way valve and operating machinery. Background Technology

[0002] Currently, in hydraulic systems where constant pressure and load-sensitive systems coexist, a separate multi-way valve and control valve assembly are typically used to control the variable pump to switch between constant pressure and load-sensitive modes. This mode requires connecting multiple ports of the multi-way valve and control valve assembly via hydraulic lines, thus requiring separate installation space for the multi-way valve and control valve assembly. Since the two need to be connected by pipes, the piping layout is likely to be more complex, occupying more installation space, making installation more complicated, and increasing the risk of oil leakage. Summary of the Invention

[0003] The purpose of this application is to provide a multi-way valve and operating machinery to solve the technical problems of complex pipeline layout, complex installation and large space occupation in existing hydraulic systems with constant pressure and load-sensitive modes.

[0004] To achieve the above objectives, this application provides a multi-way valve, comprising: The valve body has a first load feedback oil circuit inside, and the first load feedback oil circuit has a first load feedback oil port. The load-sensitive circuit includes a first oil inlet, a second load feedback oil inlet, and a second load feedback oil circuit. The first oil inlet is used to connect to the oil outlet of the first variable pump, and the second load feedback oil inlet is used to connect to the control oil inlet of the first variable pump. The second load feedback oil inlet and the first load feedback oil inlet are connected through an internal oil circuit on the valve body. The load-sensitive circuit is used to control the first variable pump to work in the load-sensitive mode, and the second load feedback oil circuit is used to feed back the maximum load pressure of the actuator to the first load feedback oil circuit. The constant pressure output and mode switching circuit shall be at least one. The constant pressure output and mode switching circuit shall be provided with a second oil inlet, a third load feedback oil inlet and a constant pressure output oil inlet. The second oil inlet shall be used to connect to the oil outlet of the second variable pump, the third load feedback oil inlet shall be used to connect to the control oil inlet of the second variable pump, and the constant pressure output and mode switching circuit shall be used to control the second variable pump to switch between load sensitive mode and constant pressure mode. The load-sensitive circuit and the constant pressure output and mode switching circuit are integrated on the valve body. In the load-sensitive mode, the oil circuits of the third load feedback port and the second load feedback port are connected, while the oil circuits of the second inlet port and the third load feedback port are disconnected. In the constant pressure mode, the oil circuits of the second load feedback port and the load pressure feedback port are disconnected, while the oil circuits of the second load feedback port, the second inlet port, and the constant pressure output port are connected.

[0005] In some implementations, there are multiple constant pressure output ports, and the constant pressure output and mode switching circuit includes: The constant pressure output line includes a first reversing valve, one side of which is connected to multiple constant pressure output ports, and the other side of which is connected to a second inlet port. The dual-mode switching system includes a switching valve, with one port of the switching valve connected to the first load feedback port oil circuit and the other port connected to the second load feedback port oil circuit. The pressure reducing oil circuit is connected to the first oil inlet at one end and to both the first directional valve and the switching valve at the other end. The pressure reducing oil circuit is used to drive the switching valve to switch so that the second variable pump can switch between load-sensitive mode and constant pressure mode. In constant pressure mode, the action of the first directional valve enables the second oil inlet to connect with one of the constant pressure output ports.

[0006] In some embodiments, the first directional valve is a three-position six-way directional valve, and the multiple constant pressure output ports include a first constant pressure output port and a second constant pressure output port. When the first directional valve switches to the first neutral position, the first oil inlet is connected to the second oil inlet, and both the first variable pump and the second variable pump operate in load-sensitive mode. When the first reversing valve switches to the first working position, the second constant pressure output port is connected to the second inlet port. The first variable pump and the second variable pump are controlled to work independently at the same time, or the first variable pump is controlled to stop working, depending on the working conditions of the machine. When the first directional valve switches to the second working position, the first constant pressure output port is connected to the second inlet port. Depending on the working conditions of the machinery, the first variable pump and the second variable pump can be controlled to work independently at the same time, or the first variable pump can be controlled to stop working.

[0007] In some embodiments, the pressure-reducing oil circuit includes a first pressure-reducing oil circuit and a second pressure-reducing oil circuit, and the constant pressure output line also includes: The first reversing drive oil circuit is connected to the first decompression oil circuit; The first electro-proportional pressure reducing valve is located on the first reversing drive oil circuit. The oil inlet of the first electro-proportional pressure reducing valve is connected to the first pressure reducing oil circuit, and the oil outlet is connected to the first control chamber of the first reversing valve. The second electro-proportional pressure reducing valve is located on the second pressure reducing oil line, and the oil outlet of the second electro-proportional pressure reducing valve is connected to the second control chamber of the first directional valve. The energization or de-energization of the first and second electro-proportional pressure reducing valves is used to drive the first directional valve to switch between the first working position, the first neutral position, and the second working position.

[0008] In some implementations, the switching valve is a two-position three-way switching valve, and the dual-mode switching connection includes: The second reversing drive oil circuit is connected to the first pressure reducing oil circuit; The third electro-proportional pressure reducing valve is located on the second reversing drive oil circuit. The oil inlet of the third electro-proportional pressure reducing valve is connected to the first pressure reducing oil circuit, and the oil outlet is connected to the control chamber of the switching valve. The energization or de-energization of the third electro-proportional pressure reducing valve is used to drive the switching valve to switch between the first switching position and the second switching position. In the first switching position, the second variable pump is in load sensitive mode, and in the second switching position, the second variable pump is in constant pressure mode.

[0009] In some implementations, the load-sensitive loop includes: Two working oil ports; The first oil inlet passage has a first oil inlet port; The second load feedback oil circuit has one end connected to the first oil inlet circuit and the other end connected to the first branch oil circuit and the second branch oil circuit. The second directional valve has its first side port connected to both working ports and the first branch oil circuit, and its second side port connected to the first inlet oil circuit, the second branch oil circuit, and the return oil circuit.

[0010] In some embodiments, a pressure compensation valve is provided in the second load feedback oil circuit. One side port of the pressure compensation valve is connected to the second side port of the second directional valve, and the other side port is connected to the first side port of the second directional valve. The first control chamber of the pressure compensation valve is connected to the first branch oil circuit, and the second control chamber of the pressure compensation valve is connected to the first load feedback oil circuit. The operation of the pressure compensation valve is used to control the connection or disconnection of the first branch oil circuit.

[0011] In some embodiments, the pressure-reducing oil circuit includes a first pressure-reducing oil circuit and a second pressure-reducing oil circuit, and the load-sensitive circuit further includes: The third reversing drive oil circuit is connected to the second pressure reducing oil circuit; The fourth electro-proportional pressure reducing valve is located on the third reversing drive oil circuit. The oil inlet of the fourth electro-proportional pressure reducing valve is connected to the first pressure reducing oil circuit, and the oil outlet is connected to the first control chamber of the second reversing valve. The fourth reversing drive oil circuit is connected to the first pressure reducing oil circuit; The fifth electro-proportional pressure reducing valve is located on the fourth directional drive oil circuit. The fifth electro-proportional pressure reducing valve is connected to the first pressure reducing oil circuit, and its outlet end is connected to the second control chamber of the second directional valve. The energization or de-energization of the fourth and fifth electro-proportional pressure reducing valves is used to drive the second directional valve to switch between the first directional position, the second neutral position, and the second directional position.

[0012] In some embodiments, the valve body is provided with a second oil inlet, a first constant pressure output oil port, and a second constant pressure output oil port, and the first directional valve includes: A first valve body is provided on the valve body. The first valve body has a first oil passage, a second oil passage, and a third oil passage that are respectively connected to the second oil inlet, the first constant pressure output oil port, and the second constant pressure output oil port. The first control chamber and the second control chamber are formed between the axial ends of the first valve body and the valve body. The first control chamber and the second control chamber are respectively connected to the oil outlet of the first electro-proportional pressure reducing valve and the second electro-proportional pressure reducing valve. The valve stem is axially inserted into the first valve body. The valve stem has a first oil groove and a second oil groove. When oil enters the first control chamber or the second control chamber, it can drive the valve stem to move axially so that the first oil groove connects the second oil inlet to the first constant pressure output oil port, or the second oil groove connects the second oil inlet and the second constant pressure output oil port.

[0013] In some embodiments, the valve body is provided with a second reversing drive oil circuit, a first mounting channel for the integrated installation of the switching valve, and a second mounting channel for the integrated installation of the third electro-proportional pressure reducing valve. A first switching control chamber is formed between the control end of the third electro-proportional pressure reducing valve and the bottom wall of the second mounting channel. A second switching control chamber is formed between the control port of the switching valve and the bottom wall of the first mounting channel. The first switching control chamber and the second switching control chamber are connected through the second reversing drive oil circuit.

[0014] A second aspect of this application provides a working machine, including a first variable pump, a second variable pump, and a multi-way valve as described above.

[0015] The above technical solution includes a valve body and a load-sensitive circuit and a constant pressure output and mode switching circuit integrated on the valve body. The valve body has a first load feedback oil circuit with a first load feedback port. The load-sensitive circuit includes a first inlet, a second load feedback port, and a second load feedback oil circuit. The first inlet is connected to the outlet of the first variable pump, and the second load feedback port is connected to the control port of the first variable pump. The second load feedback port is connected to the first load feedback port. The load-sensitive circuit controls the first variable pump to operate in load-sensitive mode, and the second load feedback oil circuit feeds back the maximum load pressure of the actuator to the first load feedback oil circuit. The system includes a feedback oil circuit and a constant pressure output and mode switching circuit, with at least one such circuit. This circuit has a second oil inlet, a third load feedback oil port, and a constant pressure output oil port. The second oil inlet connects to the outlet of the second variable pump, and the third load feedback oil port connects to the control port of the second variable pump. The constant pressure output and mode switching circuit controls the second variable pump to switch between load-sensitive mode and constant pressure mode. In load-sensitive mode, the oil circuits of the third and second load feedback oil ports are connected, while the second oil inlet and the third load feedback oil port are disconnected. In constant pressure mode, the oil circuits of the third and second load feedback oil ports are disconnected, while the oil circuits of the third load feedback oil port, the second oil inlet, and the constant pressure output oil port are connected. This application integrates load-sensitive and constant pressure functions into a single multi-way valve, allowing for free control of the multi-way valve for either load-sensitive or constant pressure functions. This reduces installation space, increases integration, simplifies piping and installation, saves piping, and reduces costs.

[0016] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] 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. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic diagram of the hydraulic principle of the multi-way valve in this application; Figure 2 This is a schematic diagram of the structure of the multi-way valve in this application; Figure 3 This is a schematic diagram of the constant pressure output section in the multi-way valve of this application; Figure 4 This is a schematic diagram of the dual-mode switching linkage in the multi-way valve of this application.

[0018] Explanation of reference numerals in the attached figures L1, First load feedback oil circuit; L3, First pressure reducing oil circuit; L2, Second pressure reducing oil circuit; L4, First reversing drive oil circuit; L5, Second reversing drive oil circuit; L6, Third reversing drive oil circuit; L7, First oil inlet oil circuit; L8, Second load feedback oil circuit; L9, First branch oil circuit; L10, Second branch oil circuit; L11, Fourth reversing drive oil circuit; 10, Load-sensitive circuit; 11, Load-sensitive reversing connection; 20, Constant pressure output and mode switching circuit; 21, Constant pressure output connection; 22, Dual mode switching connection; 30, Switching valve; 40, First reversing valve; 401, First valve body; 402, Valve stem; 403, First oil passage; 404, Second oil passage; 405, Third oil passage; 406, First control chamber; 407, Second control chamber; 408, First oil tank. ; 409, Second oil tank; 41, Second directional valve; 51, First electro-proportional pressure reducing valve; 52, Second electro-proportional pressure reducing valve; 53, Third electro-proportional pressure reducing valve; 54, Fourth electro-proportional pressure reducing valve; 55, Fifth electro-proportional pressure reducing valve; 60, Pressure compensation valve; LS, First load feedback port; LS1, Second load feedback port; LS2, Third load feedback port; P1, First oil inlet; P2, Second oil inlet; P3, First constant pressure output port; P4, Second constant pressure output port; P5, Backup oil source inlet; A, First working port; B, Second working port; T1, First return port; T2, Second return port; 100, Valve body; 101, First installation channel; 102, Second installation channel; 103, First switching control chamber; 104, Second switching control chamber. Detailed Implementation

[0019] 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.

[0020] The following description, with reference to the accompanying drawings, describes a multi-way valve and operating machinery according to this application.

[0021] like Figure 1 and Figure 2As shown, this application proposes a multi-way valve, including a valve body 100 and a load-sensitive circuit 10 and a constant pressure output and mode switching circuit 20 integrated on the valve body 100; a first load feedback oil circuit L1 is opened inside the valve body, and the first load feedback oil circuit L1 has a first load feedback oil port LS; the first load feedback oil circuit L1 has a first load feedback oil port LS; the load-sensitive circuit 10 is provided with a first oil inlet P1 and a second load feedback oil port LS1, the first oil inlet P1 is used to connect to the oil outlet of a first variable pump, and the second load feedback oil port LS1 is used to connect to the outlet of a second variable pump. The first variable pump has a control port, a second load feedback port LS1, and a first load feedback port LS2 connected via an internal oil passage on the valve body 100. The load-sensitive circuit 10 controls the first variable pump to operate in load-sensitive mode, thus ensuring that the first variable pump only has one load-sensitive operating mode. There is at least one constant pressure output and mode switching circuit 20, which includes a second inlet, a third load feedback port LS2, and a constant pressure output port. The second inlet is connected to the outlet of the second variable pump, and the third load feedback port LS2... S2 is used to connect to the control port of the second variable pump. The constant pressure output and mode switching circuit 20 is used to control the second variable pump to switch between load-sensitive mode and constant pressure mode. In load-sensitive mode, the oil circuit of the third load feedback port LS2 and the second load feedback port LS1 is connected, while the second inlet and the third load feedback port LS2 are disconnected. Thus, the pressures of the third load feedback port LS2 and the second load feedback port LS1 are equal. Since the second load feedback port LS1 is connected to the first load feedback port LS, the pressure oil of the second load feedback port LS1 is fed back to the control port of the second variable pump through the third load feedback port LS2, so that the second variable pump is in load-sensitive mode. In constant pressure mode, the oil circuit of the third load feedback port LS2 and the second load feedback port LS1 is disconnected, while the oil circuit between the third load feedback port LS2, the second inlet, and the constant pressure output port is connected. At this time, the pressures of the third load feedback port LS2 and the second inlet are equal, and the hydraulic oil in the second inlet is constant. The pressure is fed back to the control port of the second variable pump through the third load feedback port LS2, so that the second variable pump is in constant pressure mode.

[0022] Furthermore, the second load feedback oil circuit L8 is used to feed back the maximum load pressure of the actuator to the first load feedback oil circuit L1. When the second variable pump is in load-sensitive mode, both the first and second variable pumps operate in load-sensitive mode. At this time, the third load feedback oil port LS2 and the second load feedback oil port LS1 are both connected to the first load feedback oil circuit L1. The maximum load pressure of the actuator obtained by the second load feedback oil circuit L8 is fed back to the first load feedback oil circuit L1, and then fed back to the third load feedback oil port LS2 and the second load feedback oil port LS1 through the first load feedback oil circuit L1, thereby realizing the adjustment of the flow rate of the first and second variable pumps according to the load pressure. When the second variable pump is in constant pressure mode and the first variable pump is in load-sensitive mode, the maximum load pressure of the actuator obtained by the second load feedback oil circuit L8 is fed back to the first load feedback oil circuit L1, and then fed back to the second load feedback oil port LS1 through the first load feedback oil circuit L1, thereby realizing the adjustment of the flow rate of the first variable pump according to the load pressure. It should be noted that the second load feedback oil circuit L8 can obtain the load pressure of the actuators of multiple working links and select the maximum load pressure for feedback.

[0023] In this embodiment, both the first return port T1 and the second return port T2 are connected to the oil tank. This application designs the constant pressure function and the dual-mode switching function as a constant pressure output link 21 and a dual-mode switching link 22 with a plate structure, and integrates these two links into a plate multi-way valve with load-sensing function, thus forming a multi-way valve that integrates constant pressure function and load-sensing function. Thus, the multi-way valve enables the second variable pump to switch between dual modes while ensuring the load-sensing function of the first variable pump.

[0024] This application integrates the load-sensing and constant-pressure functions of a variable pump into a multi-way valve, and can freely control the multi-way valve to be used for either load-sensing or constant-pressure functions through dual-mode switching. It does not require additional piping connections or additional installation space, making the piping layout simpler, reducing installation space, and achieving high integration. Piping and installation are simpler, saving piping and reducing costs.

[0025] It should be noted that the first variable pump in this application only has a load-sensitive function and operates in load-sensitive mode during operation; the second variable pump has both load-sensitive and constant-pressure functions, and can switch between load-sensitive and constant-pressure modes through a constant-pressure output and mode switching circuit 20. During operation, the operating status and cooperative operating modes of the two variable pumps can be controlled according to the operating conditions required by the system.

[0026] Furthermore, such as Figure 1The example shown is an embodiment with one second variable pump. Of course, in other embodiments, the number of second variable pumps in this application can be two or more. When the number of variable pumps is two or more, a corresponding number of constant pressure outputs and mode switching circuits 20 can be used to connect multiple second variable pumps one by one. The control principle is similar to the mode control principle of one second variable pump, and will not be described in detail here.

[0027] In some embodiments, there are multiple constant pressure output ports. The constant pressure output and mode switching circuit 20 includes a constant pressure output link 21, a dual-mode switching link 22, and a pressure reducing oil circuit. The constant pressure output link 21 includes a first directional valve 40, one side of which is connected to multiple constant pressure output ports, and the other side of which is connected to a second inlet port. The dual-mode switching link 22 includes a switching valve 30, one side of which is connected to a first load feedback port LS oil circuit, and the other side of which is connected to a second load feedback port LS1. One end of the pressure reducing oil circuit is connected to a first inlet port P1, and the other end is connected to both the first directional valve 40 and the switching valve 30. The pressure reducing oil circuit is used to drive the switching valve 30 to switch so that the second variable pump switches between load-sensitive mode and constant pressure mode. In constant pressure mode, the action of the first directional valve 40 enables the second oil inlet to connect with one of the constant pressure output ports.

[0028] In this embodiment, when the switching valve 30 is in the upper first switching position, the third load feedback port LS2 is connected to the second load feedback port LS1. At this time, the port pressure of the third load feedback port LS2 is equal to the port pressure of the second load feedback port LS1. The pressure of the second load feedback port LS1 is fed back to the variable mechanism port of the second variable pump, making the second variable pump operate in load-sensitive mode. When the switching valve 30 is switched to the lower second switching position, the third load feedback port LS2 is connected to the second inlet port P2. The third load feedback port LS2 feeds back the pressure of the second inlet port P2. Since the pressure of the second inlet port P2 is constant, the second variable pump operates in constant pressure mode. Because the second inlet port is connected to one side of the port of the first directional valve 40, it can be ensured that in constant pressure mode, as the first directional valve 40 reverses, the second inlet port P2 is always connected to one of the constant pressure output ports. That is, the second variable pump outputs constant pressure oil from the second inlet port P2 to the constant pressure output port to provide constant pressure oil supply to the actuator.

[0029] In some embodiments, the first reversing valve 40 is a three-position six-way reversing valve with two constant pressure output ports, namely the first constant pressure output port P3 and the second constant pressure output port P4. In addition, the constant pressure output connection also includes a backup oil source inlet P5, which is used to connect a backup oil pump to supply oil to the first working oil port A and the second working oil port B in standby mode in conjunction with the first oil inlet P1. When the first reversing valve 40 switches to the first working position, the second constant pressure output oil port P4 is connected to the second oil inlet. The first variable pump and the second variable pump are controlled to work independently at the same time, or the first variable pump is controlled to stop working, depending on the working conditions of the machine. When the first reversing valve 40 switches to the second working position, the first constant pressure output oil port P3 is connected to the second oil inlet. The first variable pump and the second variable pump are controlled to work simultaneously or the first variable pump is controlled to stop working, depending on the working conditions of the machine. When the first directional valve 40 switches to the first neutral position, the first oil inlet P1 and the second oil inlet P2 are connected. The hydraulic oil from the first oil inlet P1 and the second oil inlet P2 simultaneously supplies oil to the actuator connected to the output port of the load-sensitive circuit. At this time, both the first variable pump and the second variable pump operate in load-sensitive mode.

[0030] When the first directional valve 40 switches to the first working position, the constant pressure oil from the second inlet is output to the actuator through the second constant pressure output port P4. At this time, the first variable pump can be controlled to stop working or operate independently in load-sensitive mode according to the working conditions required by the working machinery. When the first directional valve 40 switches to the second working position, the constant pressure oil from the second inlet is output to the actuator through the first constant pressure output port P3. At this time, the first variable pump can also be controlled to stop working or operate independently in load-sensitive mode according to the working conditions required by the working machinery.

[0031] In some embodiments, the pressure-reducing oil circuit includes a first pressure-reducing oil circuit L3 and a second pressure-reducing oil circuit L2, and the constant pressure output link 21 further includes: The first reversing drive oil circuit L4 is connected to the first pressure reducing oil circuit L3; The first electro-proportional pressure reducing valve 51 is located on the first reversing drive oil circuit L4. The oil inlet of the first electro-proportional pressure reducing valve 51 is connected to the first pressure reducing oil circuit L3, and the oil outlet is connected to the first control chamber of the first reversing valve 40. The second electro-proportional pressure reducing valve 52 is installed on the second pressure reducing oil circuit L2, and the oil outlet end of the second electro-proportional pressure reducing valve 52 is connected to the second control chamber of the first directional valve 40. The energization or de-energization of the first electro-proportional pressure reducing valve 51 and the second electro-proportional pressure reducing valve 52 is used to drive the first directional valve 40 to switch between the first working position, the first neutral position, and the second working position.

[0032] In this embodiment, the pressure reducing port PRC of the first pressure reducing oil circuit L3 is connected to the first oil inlet P1, meaning that the hydraulic oil pressure at the pressure reducing port of the first pressure reducing oil circuit L3 is equal to that at the first oil inlet P1; the pressure reducing port of the second pressure reducing oil circuit L2 is connected to the first oil inlet P1, meaning that the hydraulic oil pressure at the pressure reducing port of the second pressure reducing oil circuit L2 is equal to that at the first oil inlet P1. When the hydraulic oil at the first oil inlet P1 is pressure-reduced by the electro-proportional solenoid valve on the first pressure reducing oil circuit L3 or the second pressure reducing oil circuit L2, the hydraulic oil flowing to the first directional valve 40 is in a low-pressure state, approximately 2.2 MPa. When the first electro-proportional pressure reducing valve 51 is de-energized, the first directional valve 40 is in the first neutral position, and the first variable pump and the second variable pump will be in load-sensitive mode, jointly outputting hydraulic oil through the first working port A and the second working port B to the required actuator or component. When the first electro-proportional pressure reducing valve 51 is energized, the oil outlet of the first electro-proportional pressure reducing valve 51 is connected to the lower control chamber of the first directional valve 40. The output pressure oil of the first pressure reducing oil circuit L3 reaches the lower control chamber of the first directional valve 40 through the first electro-proportional pressure reducing valve 51, causing the first directional valve 40 to switch to the lower first working position, connecting the second oil inlet P2 with the first constant pressure output oil port P3, so that the constant pressure oil is output to the required actuator or component through the first constant pressure output oil port P3. When the second electro-proportional pressure reducing valve 52 is energized, the oil outlet of the second electro-proportional pressure reducing valve 52 is connected to the upper control chamber of the first directional valve 40. The hydraulic oil from the first inlet P1 passes through the PRC output pressure port of the second pressure reducing oil circuit L2 and reaches the upper control chamber of the first directional valve 40 via the second electro-proportional pressure reducing valve 52, causing the first directional valve 40 to switch to the upper second working position, connecting the second inlet P2 with the second constant pressure output port P4, thereby allowing the constant pressure oil to be output to the required actuator or component through the second constant pressure output port P4.

[0033] Compared to existing technologies that use three solenoid valves and three logic valves to achieve constant pressure, the constant pressure output link 21 of this application consists of a first electro-proportional pressure reducing valve 51, a second electro-proportional pressure reducing valve 52, and a first directional valve 40. The first and second electro-proportional pressure reducing valves 51 and 52, which control the constant pressure output switching, switch to low pressure under the pressure reduction action of the pressure reducing oil circuit, resulting in high reliability of the electro-proportional pressure reducing valves. Simultaneously, it achieves LS feedback control of the second variable pump in load-sensitive mode, independent output of multiple constant pressure oil channels in constant pressure mode, and active and flexible switching between the two operating modes, while improving the reliability of mode switching.

[0034] In summary, the return oil of the constant pressure output link 21 is connected to the return oil of the load-sensitive multi-way valve through the valve body flow channel, eliminating the need for a pipeline from the control valve group to the multi-way valve. Furthermore, the inlet oil of the constant pressure output link 21 is connected to the first inlet oil line L7 of the load-sensitive oil circuit through the valve body flow channel, saving the pipeline between the control valve group inlet and the multi-way valve inlet. Additionally, the inlets of the first electro-proportional pressure reducing valve 51 and the second electro-proportional pressure reducing valve 52 in the constant pressure output link 21 are connected to the first pressure reducing oil line L3 and the second pressure reducing oil line L2, respectively, and the return oil port is connected to the T0 oil circuit. Thus, the constant pressure output link 21 and the dual-mode switching link 22 of the second variable pump are integrated with the load-sensitive circuit 10 of the first variable pump into a single multi-way valve.

[0035] In some embodiments, the switching valve 30 is a two-position three-way switching valve 30, and the dual-mode switching link 22 includes: The second reversing drive oil circuit L5 is connected to the first pressure reducing oil circuit L3; The third electro-proportional pressure reducing valve 53 is located on the second reversing drive oil circuit L5. The oil inlet of the third electro-proportional pressure reducing valve 53 is connected to the first pressure reducing oil circuit L3, and the oil outlet is connected to the control chamber of the switching valve 30. The energization or de-energization of the third electro-proportional pressure reducing valve 53 is used to drive the switching valve 30 to switch between the first switching position and the second switching position. In the first switching position, the second variable pump is in the load sensitive mode, and in the second switching position, the second variable pump is in the constant pressure mode. When the second variable pump is in load-sensitive mode, both the first and second variable pumps operate independently in load-sensitive mode simultaneously.

[0036] In this embodiment, when the third electro-proportional pressure reducing valve 53 is energized, the switching valve 30 switches to the lower second switching position, and the second variable pump is in constant pressure mode. At this time, the constant pressure output link 21 is working. Specifically, when the third electro-proportional pressure reducing valve 53 is energized, the hydraulic oil after pressure reduction in the first pressure reducing oil circuit L3 acts on the switching valve 30, causing the switching valve 30 to switch to the lower second switching position. The third load feedback port LS2 is disconnected from the second load feedback port LS1, and the second inlet port P2 is connected to the second load feedback port LS1. The oil in the second inlet port P2 is transmitted to the third load feedback port LS2 through the switching valve 30, and then fed back to the variable mechanism port of the second variable pump, so that the second variable pump is in constant pressure mode.

[0037] When switched to the first switching position above, the second variable pump is in load-sensitive mode. The third load feedback port LS2 is connected to the second load feedback port LS1. At this time, the second load feedback port LS1 corresponds to the control port of the first variable pump. The hydraulic oil from the second load feedback port LS1 is transferred to the third load feedback port LS2 through the switching valve 30, and then fed back to the variable mechanism port of the second variable pump, making the second variable pump operate in load-sensitive mode. When the first variable pump is operating in load-sensitive mode, there is no need to shut down the second variable pump. The first and second variable pumps simultaneously supply oil to the actuator corresponding to the first working port A or the second working port in load-sensitive mode. Since both are in load-sensitive mode at this time, the output hydraulic oil of the first and second variable pumps can be adjusted according to the flow rate required by the actuator. In this operating mode, when the actuator corresponding to the first variable pump is working, there is no need to shut down the second variable pump. Furthermore, since both pumps are operating in load-sensitive mode, the output hydraulic oil of the pumps can be better utilized, preventing waste of hydraulic oil from one of them.

[0038] In some embodiments, the load-sensitive circuit 10 includes a load-sensitive reversing link 11, wherein the load-sensitive reversing link 11 includes two working oil ports, a first oil inlet circuit L7, a second load feedback circuit L8, and a second reversing valve 41; the first oil inlet circuit L7 has a first oil inlet P1; one end of the second load feedback circuit L8 is connected to the first oil inlet circuit L7, and the other end is connected to a first branch circuit L9 and a second branch circuit L10; The second directional valve 41 is a three-position six-way directional valve. The first side port of the second directional valve 41 is connected to the two working ports and the first branch oil circuit L9. The second side port is connected to the first inlet oil circuit L7, the second branch oil circuit L10 and the return oil circuit.

[0039] In this embodiment, the two working ports are designated as first working port A and second working port B, respectively, and are connected to different actuators. The second load feedback oil circuit L8 branches into first branch oil circuit L9 and second branch oil circuit L10. By connecting the first branch oil circuit L9 and the second branch oil circuit L10 to the two sides of the second directional valve 41, when the second switching valve 30 is switched to the neutral position, the first branch oil circuit L9 and the first inlet oil circuit L7 are disconnected, the first working port A and the first return oil circuit are connected, and the second working port is connected to the second branch oil circuit L10. When the second switching valve 30 is switched to the upper first working position, the first branch oil circuit L9 and the first inlet oil circuit L7 are connected, and the first inlet oil circuit P1 supplies hydraulic oil to the second working port through the second branch oil circuit L10. At this time, the first working port A returns oil through the first return oil circuit. When the second switching valve 30 switches to the lower second working position, the first branch oil circuit L9 and the first inlet oil circuit L7 are connected, the first working oil port A and the second branch oil circuit L10 are connected, and the second working oil port is connected to the first return oil circuit, thereby realizing the switching of different working oil ports. The load pressure of different working oil ports is obtained through the first branch oil circuit L9 or the second branch oil circuit L10, and finally fed back to the control oil port of the variable pump through the second load feedback oil circuit L8.

[0040] In some embodiments, a pressure compensation valve 60 is provided on the second load feedback oil circuit L8. One side port of the pressure compensation valve 60 is connected to the second side port of the second directional valve 41, and the other side port is connected to the first side port of the second directional valve 41. The first control chamber of the pressure compensation valve 60 is connected to the first branch oil circuit L9, and the second control chamber of the pressure compensation valve 60 is connected to the first load feedback oil circuit L1. The operation of the pressure compensation valve 60 is used to control the connection or disconnection of the first branch oil circuit L9.

[0041] In this embodiment, the load-sensing function of the first variable pump mainly consists of a first load feedback oil circuit L1, a second load feedback oil circuit L8, a second directional valve 41, and a pressure compensation valve 60. The pressure compensation valve 60 is a three-position two-way directional valve; when the pressure compensation valve 60 switches to... Figure 1 In the lower position shown, the first branch oil circuit L9 is disconnected, and the hydraulic oil in the first load feedback oil circuit L1 is used to control the output to the second control chamber of the pressure compensation valve 60. When the pressure compensation valve 60 switches to the neutral position, the first branch oil circuit L9 is connected, and a portion of the hydraulic oil in the first branch oil circuit L9 enters the first control chamber of the pressure compensation valve 60. At the same time, the hydraulic oil in the first load feedback oil circuit L1 enters the second control chamber of the pressure compensation valve 60. In this embodiment, the pressure compensation valve 60 maintains a constant pressure difference across the throttle port, ensuring that the flow rate is not affected by fluctuations in load pressure and supply pressure, thereby maintaining a stable oil port pressure entering the second directional valve 41.

[0042] In some embodiments, the load-sensitive circuit 10 further includes a third reversing drive oil circuit L6, a fourth electro-proportional pressure reducing valve 54, a fourth reversing drive oil circuit L11, and a fifth electro-proportional pressure reducing valve 55; the third reversing drive oil circuit L6 is connected to the second pressure reducing oil circuit L2; the fourth electro-proportional pressure reducing valve 54 is disposed on the third reversing drive oil circuit L6, the inlet end of the fourth electro-proportional pressure reducing valve 54 is connected to the first pressure reducing oil circuit L3, and the outlet end is connected to the first control chamber of the second reversing valve 41; the fourth reversing drive oil circuit L11 is connected to the first pressure reducing oil circuit L3; the fifth electro-proportional pressure reducing valve 55 is disposed on the fourth reversing drive oil circuit L11, the fifth electro-proportional pressure reducing valve 55 is connected to the first pressure reducing oil circuit L3, and the outlet end is connected to the second control chamber of the second reversing valve 41; the energization or de-energization of the fourth electro-proportional pressure reducing valve 54 and the fifth electro-proportional pressure reducing valve 55 is used to drive the second reversing valve 41 to switch between the first reversing position, the second neutral position, and the second reversing position.

[0043] Because the load-sensitive function allows the variable pump to sense the load demand and output corresponding pressure and flow rate accordingly. In this embodiment, when the first variable pump is working, it only operates in load-sensitive mode, i.e., supplying oil on demand. Specifically, when the fourth electro-proportional pressure reducing valve 54 is energized, the pressure at the PRC port on the second pressure reducing oil circuit L2 is transmitted to the control chamber of the second reversing valve 41 through the fourth electro-proportional pressure reducing valve 54, pushing the valve core to reverse, so that the first oil inlet P1 is connected to the second working oil port B. The current of the fourth electro-proportional pressure reducing valve 54 can be controlled so that the valve core throttle opening changes with the current. At this time, the pressure at the output port of the first variable pump will change accordingly. The multi-way valve feeds back the pressure at the first load feedback port LS to the variable mechanism of the first variable pump through the second load feedback port LS1. The variable mechanism detects P 泵 ≠P LS With +ΔP, the variable displacement mechanism will adjust the displacement accordingly, so that the first variable pump outputs the required flow rate according to the change of the valve core opening of the second reversing valve 41, in order to achieve P 泵 =P LS +ΔP, thus maintaining stability. When the load changes, the multi-way valve maintains a constant pressure difference across the throttling orifice of the second directional valve 41 through the pressure compensation valve 60, so that the flow rate at the throttling orifice is only related to the opening degree and not to the load pressure.

[0044] like Figure 3 As shown, the valve body 100 is provided with a second oil inlet P2, a first constant pressure output oil port P3, and a second constant pressure output oil port P4. The first directional valve 40 includes: A first valve body 401 is disposed on a valve body 100. The first valve body 401 has a first oil passage 403, a second oil passage 404 and a third oil passage 405 that are respectively connected to the second oil inlet P2, the first constant pressure output oil port P3 and the second constant pressure output oil port P4. The first control chamber 406 and the second control chamber 407 are formed between the two axial ends of the first valve body 401 and the valve body 100. The first control chamber 406 and the second control chamber 407 are respectively connected to the oil outlets of the first electro-proportional pressure reducing valve 51 and the second electro-proportional pressure reducing valve 52. The valve stem 402 is axially movably inserted into the first valve body 401. The valve stem 402 has a first oil groove 408 and a second oil groove 409. When oil enters the first control chamber 406 or the second control chamber 407, it can drive the valve stem 402 to move axially, so that the first oil groove 408 connects the second oil inlet P2 with the first constant pressure output oil port P3, or the second oil groove 409 connects the second oil inlet P2 and the second constant pressure output oil port P4.

[0045] In this embodiment, by opening multiple oil passages on the first valve body 401, when the first electro-proportional pressure reducing valve 51 or the second electro-proportional pressure reducing valve 52 is energized or de-energized, the hydraulic oil pressure in the first control chamber 406 and the second control chamber 407 becomes unbalanced, thereby driving the valve stem 402 to move axially. When the valve stem 402 moves axially, when the first oil groove 408 corresponds to the second oil inlet P2 and the first constant pressure output oil port P3, the second oil inlet P2 and the first constant pressure output oil port P3 can be connected; when the second oil groove 409 corresponds to the second oil inlet P2 and the second constant pressure output oil port P4, the second oil inlet P2 and the second constant pressure output oil port P4 can be connected.

[0046] like Figure 4 As shown, the valve body 100 is provided with a second reversing drive oil circuit L5, a first mounting channel 101 for the integrated installation of the switching valve 30, and a second mounting channel 102 for the integrated installation of the third electro-proportional pressure reducing valve 53. A first switching control chamber 103 is formed between the control end of the third electro-proportional pressure reducing valve 53 and the bottom wall of the second mounting channel 102. A second switching control chamber 104 is formed between the control oil port of the switching valve and the bottom wall of the first mounting channel 101. The first switching control chamber 103 and the second switching control chamber 104 are connected through the second reversing drive oil circuit L5.

[0047] In this embodiment, by integrating the switching valve 30 and the third electro-proportional pressure reducing valve 53 into the mounting channel on the valve body 100, the installation space of the entire valve body 100 can be fully utilized, the pipeline is optimized, and costs are saved.

[0048] A second aspect of this application provides a working machine, including a first variable pump, a second variable pump, and a multi-way valve as described above. The working machine can be a crane. When the crane is in hoisting, telescopic, or luffing operation, the first and second variable pumps can be controlled to operate independently in load-sensitive mode simultaneously. When the crane is in superlift operation, the second variable pump is controlled to switch to constant pressure mode, at which point the first variable pump stops operating. When the crane is in boom telescopic operation and superlift also needs to operate, the second variable pump is controlled to operate in constant pressure mode, while the first variable pump operates in load-sensitive mode, and the operations of the first and second variable pumps are independent of each other.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 multi-way valve, characterized in that, include: The valve body (100) has a first load feedback oil passage (L1) inside, and the first load feedback oil passage (L1) has a first load feedback oil port (LS). The load-sensitive circuit (10) includes a first oil inlet (P1), a second load feedback oil inlet (LS1), and a second load feedback oil path (L8). The first oil inlet (P1) is used to connect to the oil outlet of the first variable pump, and the second load feedback oil inlet (LS1) is used to connect to the control oil inlet of the first variable pump. The second load feedback oil inlet (LS1) and the first load feedback oil inlet (LS) are connected through an internal oil path on the valve body (100). The load-sensitive circuit (10) is used to control the first variable pump to work in the load-sensitive mode, and the second load feedback oil path (L8) is used to feed back the maximum load pressure of the actuator to the first load feedback oil path (L1). The constant pressure output and mode switching circuit (20) has at least one such circuit. The constant pressure output and mode switching circuit (20) is provided with a second oil inlet (P2), a third load feedback oil inlet (LS2), and a constant pressure output oil inlet. The second oil inlet (P2) is used to connect to the oil outlet of the second variable pump. The third load feedback oil inlet (LS2) is used to connect to the control oil inlet of the second variable pump. The constant pressure output and mode switching circuit (20) is used to control the second variable pump to switch between load-sensitive mode and constant pressure mode. The load-sensitive circuit (10) and the constant pressure output and mode switching circuit (20) are integrated on the valve body (100). In the load-sensitive mode, the oil circuits of the third load feedback port (LS2) and the second load feedback port (LS1) are connected, and the oil circuits of the second inlet port (P2) and the third load feedback port (LS2) are disconnected. In the constant pressure mode, the oil circuits of the third load feedback port (LS2) and the second load feedback port (LS1) are disconnected, and the oil circuits of the third load feedback port (LS2), the second inlet port (P2), and the constant pressure output port are connected.

2. The multi-way valve according to claim 1, characterized in that, The number of constant pressure output ports is multiple, and the constant pressure output and mode switching circuit (20) includes: The constant pressure output link (21) includes a first reversing valve (40), one side of the first reversing valve (40) is connected to multiple constant pressure output ports, and the other side is connected to the second oil inlet (P2); The dual-mode switching link (22) includes a switching valve (30), one side of which is connected to the first load feedback port (LS) oil circuit, and the other side is connected to the second load feedback port (LS1). The pressure reducing oil circuit is connected at one end to the first oil inlet (P1) and at the other end to both the first reversing valve (40) and the switching valve (30). The pressure reducing oil circuit is used to drive the switching valve (30) to switch so that the second variable pump switches between load-sensitive mode and constant pressure mode. In the constant pressure mode, the action of the first reversing valve (40) enables the second oil inlet (P2) to be connected to one of the constant pressure output ports.

3. The multi-way valve according to claim 2, characterized in that, The plurality of constant pressure output ports include a first constant pressure output port (P3) and a second constant pressure output port (P4); When the first directional valve (40) switches to the first neutral position, the first oil inlet (P1) is connected to the second oil inlet (P2), and both the first variable pump and the second variable pump operate in load-sensitive mode. When the first reversing valve (40) switches to the first working position, the second constant pressure output oil port (P4) is connected to the second oil inlet (P2), and the first variable pump and the second variable pump are controlled to work independently at the same time according to the working conditions of the working machinery, or the first variable pump is controlled to stop working. When the first reversing valve (40) switches to the second working position, the first constant pressure output port (P3) is connected to the second oil inlet port (P2), and the first variable pump and the second variable pump are controlled to work independently at the same time according to the working conditions of the working machinery, or the first variable pump is controlled to stop working.

4. The multi-way valve according to claim 3, characterized in that, The pressure-reducing oil circuit includes a first pressure-reducing oil circuit (L3) and a second pressure-reducing oil circuit (L2), and the constant pressure output link (21) also includes: The first reversing drive oil circuit (L4) is connected to the first decompression oil circuit (L3); The first electro-proportional pressure reducing valve (51) is located on the first reversing drive oil circuit (L4). The oil inlet of the first electro-proportional pressure reducing valve (51) is connected to the first pressure reducing oil circuit (L3), and the oil outlet is connected to the first control chamber of the first reversing valve (40). The second electro-proportional pressure reducing valve (52) is provided on the second pressure reducing oil circuit (L2), and the oil outlet end of the second electro-proportional pressure reducing valve (52) is connected to the second control chamber of the first reversing valve (40). The energization or de-energization of the first electro-proportional pressure reducing valve (51) and the second electro-proportional pressure reducing valve (52) is used to drive the first reversing valve (40) to switch between the first working position, the first neutral position and the second working position.

5. The multi-way valve according to claim 4, characterized in that, The dual-mode switching link (22) includes: The second reversing drive oil circuit (L5) is connected to the first pressure reducing oil circuit (L3); The third electro-proportional pressure reducing valve (53) is located on the second reversing drive oil circuit (L5). The oil inlet of the third electro-proportional pressure reducing valve (53) is connected to the first pressure reducing oil circuit (L3), and the oil outlet is connected to the control chamber of the switching valve (30). The energization or de-energization of the third electro-proportional pressure reducing valve (53) is used to drive the switching valve (30) to switch between the first switching position and the second switching position. In the first switching position, the second variable pump is in load sensitive mode, and in the second switching position, the second variable pump is in constant pressure mode.

6. The multi-way valve according to any one of claims 2-5, characterized in that, The load-sensitive circuit (10) further includes: Two working oil ports; The first oil inlet circuit (L7) has the first oil inlet (P1). One end of the second load feedback circuit (L8) is connected to the first oil inlet circuit (L7), and the other end is connected to the first branch circuit (L9) and the second branch circuit (L10). The second directional valve (41) has a first side port that is connected to both working ports and the first branch oil circuit (L9), and a second side port that is connected to the first inlet oil circuit (L7), the second branch oil circuit (L10), and the return oil circuit.

7. The multi-way valve according to claim 6, characterized in that, The second load feedback oil circuit (L8) is provided with a pressure compensation valve (60). One side port of the pressure compensation valve (60) is connected to the second side port of the second reversing valve (41), and the other side port is connected to the first side port of the second reversing valve (41). The first control chamber of the pressure compensation valve (60) is connected to the first branch oil circuit (L9), and the second control chamber of the pressure compensation valve (60) is connected to the first load feedback oil circuit (L1). The action of the pressure compensation valve (60) is used to control the connection or disconnection of the first branch oil circuit (L9).

8. The multi-way valve according to claim 6, characterized in that, The pressure-reducing oil circuit includes a first pressure-reducing oil circuit (L3) and a second pressure-reducing oil circuit (L2), and the load-sensitive circuit (10) further includes: The third reversing drive oil circuit (L6) is connected to the second decompression oil circuit (L2); The fourth electro-proportional pressure reducing valve (54) is located on the third reversing drive oil circuit (L6). The oil inlet of the fourth electro-proportional pressure reducing valve (54) is connected to the first pressure reducing oil circuit (L3), and the oil outlet is connected to the first control chamber of the second reversing valve (41). The fourth reversing drive oil circuit (L11) is connected to the first pressure reducing oil circuit (L3); The fifth electro-proportional pressure reducing valve (55) is located on the fourth reversing drive oil circuit (L11). The fifth electro-proportional pressure reducing valve (55) is connected to the first pressure reducing oil circuit (L3), and its oil outlet is connected to the second control chamber of the second reversing valve (41). The energization or de-energization of the fourth electro-proportional pressure reducing valve (54) and the fifth electro-proportional pressure reducing valve (55) is used to drive the second reversing valve (41) to switch between the first reversing position, the second neutral position, and the second reversing position.

9. The multi-way valve according to claim 4 or 5, characterized in that, The valve body (100) is provided with a second oil inlet (P2), a first constant pressure output oil port (P3) and a second constant pressure output oil port (P4), and the first reversing valve (40) includes: A first valve body (401) is disposed on the valve body (100). The first valve body (401) has a first oil passage (403), a second oil passage (404), and a third oil passage (405) that are respectively connected to the second oil inlet (P2), the first constant pressure output oil port (P3), and the second constant pressure output oil port (P4). The first control chamber (406) and the second control chamber (407) are formed between the two axial ends of the first valve body (401) and the valve body (100). The first control chamber (406) and the second control chamber (407) are respectively connected to the oil outlets of the first electro-proportional pressure reducing valve (51) and the second electro-proportional pressure reducing valve (52). The valve stem (402) is axially inserted into the first valve body (401). The valve stem (402) has a first oil groove (408) and a second oil groove (409). When oil enters the first control chamber (406) or the second control chamber (407), the valve stem (402) can be driven to move axially, so that the first oil groove (408) connects the second oil inlet (P2) with the first constant pressure output oil port (P3), or the second oil groove (409) connects the second oil inlet (P2) and the second constant pressure output oil port (P4).

10. The multi-way valve according to claim 5, characterized in that, The valve body (100) is provided with a second reversing drive oil passage (L5), a first mounting channel (101) for the integrated installation of the switching valve (30), and a second mounting channel (102) for the integrated installation of the third electro-proportional pressure reducing valve (53). A first switching control cavity (103) is formed between the control end of the third electro-proportional pressure reducing valve (53) and the bottom wall of the second mounting channel (102). A second switching control cavity (104) is formed between the control oil port of the switching valve and the bottom wall of the first mounting channel (101). The first switching control cavity (103) and the second switching control cavity (104) are connected through the second reversing drive oil passage (L5).

11. A type of operating machinery, characterized in that, It includes a first variable pump, a second variable pump, and a multi-way valve according to any one of claims 1 to 10.

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