Multi-way valve and hydraulic system

Abstract

The multi-way valve and hydraulic system of the present disclosure relates to the technical field of hydraulics. The multi-way valve comprises a valve body, a switching valve and a working valve group. The switching valve is provided with a switching valve rod, a first chamber and a second chamber. The working valve group is provided with a working valve oil inlet. The valve body is provided with a load sensing oil passage, which is in communication with the second chamber. If the pressure difference between the working valve oil inlet and the working chamber is less than or equal to a first preset value, the switching valve rod is in a first position to make the oil passage between the first oil inlet and the working valve oil inlet conductive. If the pressure difference between the working valve oil inlet and the working chamber is greater than the first preset value, the switching valve rod is in a second position to make the oil passage between the first oil inlet and the working valve oil inlet blocked, so as to realize the combination or pressure relief and achieve the purpose of energy saving.

Description

Technical Field

[0001] This invention relates to the field of hydraulic technology, and more specifically, to a multi-way valve and a hydraulic system. Background Technology

[0002] The main working conditions of a loader are digging and loading. In order to operate efficiently, the machine needs to frequently turn left and right, and the execution module needs to frequently retract the bucket, lift, unload, and lower. All of these actions are controlled and realized by the loader's hydraulic system.

[0003] A loader's hydraulic system generally includes an actuator hydraulic system and a steering hydraulic system. In existing technology, if two pumps (such as a working pump and a steering pump) are used to control the actuator and steering mechanism separately, the hydraulic system efficiency is low, and optimal flow matching cannot be achieved during complex actions. If the actuator and steering hydraulic systems are combined into a hybrid system—where, when the steering hydraulic system is not in operation, the flow is diverted via a flow divider valve and merged with the working pump to supply oil to the loader's multi-way valve—this achieves flow merging and can optimize flow distribution to some extent. However, this results in a more complex structure, a more complex hydraulic system, and higher costs. Summary of the Invention

[0004] The objectives of this invention include, for example, providing a multi-way valve and hydraulic system that enables the merging and unloading of a steering pump and a working pump, with good energy-saving efficiency, a relatively simple structure, and reduced costs.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a multi-way valve, including a valve body and a switching valve and a working valve assembly disposed on the valve body. The valve body is provided with a first oil inlet P and a second oil inlet EF. The first oil inlet P is used to communicate with a working pump, and the second oil inlet EF is used to communicate with a steering pump.

[0007] The switching valve is provided with a switching valve stem, a first chamber, and a second chamber. The switching valve stem can move between the first chamber and the second chamber. The working valve assembly is provided with a working valve inlet, which is connected to the first chamber. The valve body is provided with a load sensing oil passage ls, which is connected to the second chamber. If the pressure difference between the working valve inlet and the second chamber is less than or equal to a first preset value, the switching valve stem is in a first position to connect the oil passage between the first inlet P and the working valve inlet. If the pressure difference between the working valve inlet and the second chamber is greater than the first preset value, the switching valve stem is in a second position to cut off the oil passage between the first inlet P and the working valve inlet.

[0008] In an optional embodiment, the valve body is provided with a return port T, a pilot inlet port and a load sensing port LS. The pilot inlet port is used to communicate with the pilot valve, and the return port T and the load sensing port LS are respectively connected to the oil tank.

[0009] The working valve assembly includes a control chamber, a working chamber, and a working valve stem. The working valve inlet is connected to the first inlet P and the second inlet EF, respectively. The pilot inlet is connected to the control chamber. Pilot oil enters the control chamber from the pilot inlet. The pilot oil is used to drive the working valve stem to move so that the working valve inlet is connected to the working chamber. The working chamber is used to connect to the execution module.

[0010] In an optional embodiment, the load sensing oil passage 1s is connected to the load sensing oil port LS, and the load sensing oil port is used to connect to the compensator of the steering pump, which can adjust the displacement of the steering pump.

[0011] In an optional embodiment, a shuttle valve is provided on the valve body, the oil inlet of the shuttle valve is connected to the regulating oil passage, and the oil outlet of the shuttle valve is connected to the load sensing oil passage 1s.

[0012] In an optional embodiment, the oil inlet of the switching valve is connected to the first oil inlet P, and the oil outlet of the switching valve is connected to the working valve group; the switching valve stem is provided with a first oil passage rsi and a second oil passage rst, the oil inlet of the switching valve is connected to the oil outlet of the switching valve via the first oil passage rsi, and the oil inlet of the switching valve is connected to the return port of the switching valve via the second oil passage rst.

[0013] In an optional embodiment, one end of the switching valve stem is provided with a first elastic element, which is disposed in the second chamber. If the pressure difference between the first chamber and the second chamber is less than or equal to the elastic force of the first elastic element, the switching valve stem is in a first position, so that the oil inlet of the switching valve is connected to the oil outlet of the switching valve through the first oil passage rsi. If the pressure difference between the first chamber and the second chamber is greater than the elastic force of the first elastic element, the switching valve stem moves to a second position, so that the oil inlet of the switching valve is connected to the oil return port of the switching valve through the second oil passage rst.

[0014] In an optional embodiment, the control chamber is provided with a second elastic element, which is connected to the working valve stem so that the working valve stem is in a third position or a fourth position.

[0015] The working valve stem is provided with a first channel, a second channel, a third channel and a fourth channel, and the working valve group is provided with a first working chamber and a second working chamber, the first working chamber and the second working chamber being respectively connected to the execution module;

[0016] The working valve stem is in the third position, the oil inlet of the working valve group is connected to the first working chamber through the first channel, and the second working chamber is connected to the oil return port through the fourth channel;

[0017] The working valve stem is in the fourth position, the oil inlet of the working valve assembly is connected to the second working chamber through the third channel, and the first working chamber is connected to the oil return port through the second channel.

[0018] In an optional embodiment, the working valve stem is provided with an adjusting oil passage, which includes a first damping hole, a second damping hole and an internal oil passage provided on the working valve stem. The first damping hole communicates with the first working chamber, the second damping hole communicates with the second working chamber, the first damping hole and the second damping hole are respectively communicated with the internal oil passage, and the internal oil passage is communicated with the load sensing oil port.

[0019] In an optional embodiment, the working valve group includes a boom control valve and a bucket control valve. The first oil inlet P is connected to the boom control valve and the bucket control valve respectively via the switching valve, and the second oil inlet EF is connected to the boom control valve and the bucket control valve respectively. The working valve stem includes a boom valve stem and a bucket valve stem. The boom valve stem is movably disposed on the boom control valve, and the bucket valve stem is movably disposed on the bucket control valve.

[0020] The pilot oil inlet includes a first pilot oil inlet, a second pilot oil inlet, a third pilot oil inlet, and a fourth pilot oil inlet. One end of the boom valve rod is connected to the first pilot oil inlet, and the other end is connected to the second pilot oil inlet. One end of the bucket valve rod is connected to the third pilot oil inlet, and the other end is connected to the fourth pilot oil inlet.

[0021] In an optional embodiment, the second elastic element includes a second spring and a third spring, with the second spring located at one end of the boom valve stem and the third spring located at one end of the bucket valve stem.

[0022] In an optional embodiment, the valve body is provided with a first return oil passage T0 and a second return oil passage T1; the valve body is provided with a back pressure valve, and the second return oil passage T1 is connected to the first return oil passage T0 via the back pressure valve.

[0023] In the boom control valve, the first working chamber includes a boom raising chamber for connection to the large chamber of the boom cylinder; the second working chamber includes a boom lowering chamber for connection to the small chamber of the boom cylinder; the return oil of the boom raising chamber is connected to the second return oil passage T1, and the return oil of the boom lowering chamber is connected to the first return oil passage T0; the first return oil passage T0 is connected to the return oil port T.

[0024] In an optional embodiment, the bucket control valve includes a first working chamber comprising a bucket collecting chamber for connection to the large chamber of the bucket cylinder; a second working chamber comprising a bucket discharging chamber for connection to the small chamber of the bucket cylinder; the return oil of the bucket collecting chamber is connected to the second return oil passage T1, and the return oil of the bucket discharging chamber is connected to the first return oil passage T0.

[0025] In an optional embodiment, the valve body is provided with a shuttle valve, which has a first oil port, a second oil port and a third oil port. The first oil port is connected to the regulating oil passage on the boom valve rod, the second oil port is connected to the regulating oil passage on the bucket valve rod, and the third oil port is connected to the load sensing oil port.

[0026] In an optional embodiment, the valve body is provided with an overflow valve, the high-pressure chamber of the overflow valve is connected to the load sensing oil passage 1s, and the return port of the overflow valve is connected to the return port T.

[0027] In an optional embodiment, a pressure reducing valve is further included, which is disposed in the control oil line between the pilot oil inlet and the control chamber.

[0028] In a second aspect, the present invention provides a hydraulic system including a working pump, a steering pump, an actuation module, and a multi-way valve as described in any of the foregoing embodiments, wherein the working pump and the steering pump are respectively connected to the multi-way valve, and the multi-way valve is connected to the actuation module.

[0029] The beneficial effects of the embodiments of the present invention include, for example:

[0030] This multi-way valve, by incorporating a switching valve stem, enables the merging of the working pump and the steering pump, optimizing flow distribution, improving work efficiency, and achieving energy savings. By installing a load-sensing oil passage on the working valve stem, oil from this passage enters the switching valve, changing the position of the valve stem to open or close the switching valve. This connects or disconnects the oil circuit between the working pump and the working valve assembly, achieving optimal flow matching between the working pump and the steering pump when merging, as well as unloading the working pump. The hydraulic system exhibits good energy efficiency and a simple, compact structure, which helps reduce costs.

[0031] The hydraulic system includes the aforementioned multi-way valve. The working pump and steering pump are connected to the multi-way valve, which is connected to the actuator module. This allows for the merging and unloading of the working pump. The hydraulic system has good energy efficiency, which helps reduce costs. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the hydraulic system provided in an embodiment of the present invention;

[0034] Figure 2 for Figure 1 A magnified schematic diagram of the hydraulic control system of the multi-way valve in the diagram;

[0035] Figure 3 for Figure 1 An enlarged schematic diagram of the hydraulic control system of the steering pump in the diagram;

[0036] Figure 4 This is a first-view structural schematic diagram of a multi-way valve provided in an embodiment of the present invention;

[0037] Figure 5 This is a second-view structural schematic diagram of the multi-way valve provided in an embodiment of the present invention;

[0038] Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure of AA;

[0039] Figure 7 for Figure 4 A schematic diagram of the structure from the perspective of the center-E direction;

[0040] Figure 8 This is a schematic diagram of the structure of the return port T of the multi-way valve provided in an embodiment of the present invention;

[0041] Figure 9 for Figure 8 A schematic diagram of the structure from a G-axis perspective;

[0042] Figure 10 for Figure 4 A schematic diagram of the cross-sectional structure of DD;

[0043] Figure 11 for Figure 4 A schematic diagram of the cross-sectional structure of CC;

[0044] Figure 12 This is a schematic cross-sectional view of the connection between the second oil inlet EF and the oil passage ef in this embodiment.

[0045] Figure 13 This is a schematic cross-sectional view of the working valve group connected to the load sensing oil passage 1s via a shuttle valve in this embodiment.

[0046] Figure 14 This is a schematic cross-sectional view of the back pressure valve in this embodiment;

[0047] Figure 15 This is a schematic cross-sectional view of the first check valve in this embodiment.

[0048] Icons: 100 - Multi-way valve; 110 - Valve body; 200 - Switching valve; 201 - Switching valve stem; 203 - First spring; CS1 - First chamber; C1S - Second chamber; 300 - Working valve assembly; 301 - Boom cylinder; 303 - Bucket cylinder; 310 - Boom control valve; 320 - Boom valve stem; 330 - Second spring; 350 - Bucket control valve; 360 - Bucket valve stem; 370 - Third spring; P - First oil inlet; EF - Second oil inlet; T - Return oil port; LS - Load sensing oil port; LS - Load sensing oil passage; RSI - First oil passage; RST - Second oil passage; T0 - First return oil passage; T1 - Second return oil passage; XA2 - First pilot oil inlet xB2 - Second pilot inlet; xA1 - Third pilot inlet; xB1 - Fourth pilot inlet; 410 - Back pressure valve; 420 - First check valve; 430 - Second check valve; 440 - Third check valve; bl - Boom lifting chamber; bd - Boom lowering chamber; bkl - Bucket collection chamber; bkd - Bucket unloading chamber; 101 - Working pump; 103 - Steering pump; 104 - Compensator; 105 - Pilot valve; 106 - Priority valve; 107 - Oil tank; 109 - System shuttle valve; 120 - Shuttle valve; 130 - Floating control valve; 140 - Floating replenishing valve; 141 - Replenishing valve; 160 - Overflow valve; 460 - Pressure reducing valve; 170 - Main safety valve; 401 - Steering gear. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0051] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0052] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0053] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0054] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0055] Please refer to Figures 1 to 15 ,in Figures 1 to 3 This is a schematic diagram of the control principle of a hydraulic system. Figures 4 to 15 The diagram shows the structure of the multi-way valve 100 from different perspectives.

[0056] This embodiment provides a multi-way valve 100, including a valve body 110 and a switching valve 200 and a working valve group 300 disposed on the valve body 110. The valve body 110 is provided with a first oil inlet P, a second oil inlet EF, a return oil inlet T, a pilot oil inlet, and a load sensing oil inlet LS. The first oil inlet P is used to communicate with the working pump 101, the second oil inlet EF is used to communicate with the steering pump 103, the pilot oil inlet is used to communicate with the pilot valve 105, and the return oil inlet T and the load sensing oil inlet LS are respectively connected to the oil tank 107. The switching valve 200 is provided with a switching valve stem 201, a first chamber CS1 and a second chamber CS1s. The switching valve stem 201 can move in the first chamber CS1 and the second chamber CS1s to realize the opening or closing of the oil circuit.

[0057] The working valve assembly 300 is provided with a control chamber, a working chamber, a working valve stem, and a working valve inlet. The working valve inlet is connected to the first inlet P and the second inlet EF, respectively. The pilot inlet is connected to the control chamber. Pilot oil enters the control chamber from the pilot inlet and is used to drive the working valve stem to move so that the working valve inlet is connected to the working chamber. The working chamber is used to connect to the execution module. The working valve stem is provided with a regulating oil passage, and the valve body 110 is provided with a load sensing oil passage ls. One end of the regulating oil passage is connected to the working chamber, and the other end is connected to the second chamber c1s via the load sensing oil passage ls. If the pressure difference between the working valve inlet and the working chamber is less than or equal to a first preset value, the switching valve stem 201 is in the first position so that the oil circuit between the first inlet P and the working valve inlet is connected. If the pressure difference between the working valve inlet and the working chamber is greater than the first preset value, the switching valve stem 201 is in the second position so that the oil circuit between the first inlet P and the working valve inlet is cut off. The multi-way valve 100, under the action of the switching valve 200, can realize the connection and disconnection of the oil circuit between the working pump 101 and the working valve group 300, that is, realize the confluence and unloading of the working pump 101, which has high energy-saving efficiency.

[0058] It should be noted that, since the oil inlet of the working valve is connected to the first chamber CS1 and the working chamber is connected to the second chamber C1s, the pressure difference between the oil inlet of the working valve and the working chamber is the pressure difference between the first chamber CS1 and the second chamber C1s on the switching valve 200.

[0059] It is understood that the second chamber c1s is equipped with a first elastic element, such as a first spring 203. The first elastic element contacts the switching valve stem 201. During operation, if the pressure difference between the working valve inlet and the second chamber c1s is small, it cannot overcome the elastic force of the first elastic element to drive the switching valve stem 201 to move. The switching valve 200 remains in the open state, and the oil from the working pump 101 reaches the working valve group 300 through the switching valve 200, merging with the hydraulic oil output from the steering pump 103 to meet the working pressure of the working chamber. During operation, if the pressure difference between the working valve inlet and the second chamber c1s is large, it overcomes the elastic force of the first elastic element to drive the switching valve stem 201 to move. The switching valve 200 switches to the closed state, and the oil circuit between the working pump 101 and the working valve group 300 is cut off by the switching valve 200. The oil from the working pump 101 flows back to the oil tank 107 after passing through the switching valve 200, achieving the purpose of unloading the working pump 101.

[0060] Optionally, the load-sensing oil passage ls is connected to the load-sensing oil port LS. The load-sensing oil port LS is used to connect to the compensator 104 of the steering pump 103, which can adjust the displacement of the steering pump 103. When the working valve assembly 300 is in operation, the pressure oil in the working chamber enters the load-sensing oil passage ls through the regulating oil passage. Part of the oil in the load-sensing oil passage ls enters the switching valve 200, and the other part reaches the compensator 104 of the steering pump 103 to adjust the displacement of the steering pump 103 to meet the flow requirements of the working chamber. It is easy to understand that if the working chamber needs to operate at high speed, the oil in the load-sensing oil passage ls acts on the compensator 104, which increases the displacement of the steering pump 103; if the working chamber needs to operate at low speed, the oil in the load-sensing oil passage ls acts on the compensator 104, which decreases the displacement of the steering pump 103.

[0061] The multi-way valve 100 can realize the merging of the working pump 101 and the steering pump 103 according to the actual flow requirements of the working valve group 300, or unload the working pump 101, and can also automatically adjust the displacement of the steering pump 103 to achieve the best flow matching, and achieve energy saving while meeting the normal working conditions of the working valve group 300.

[0062] Optionally, a shuttle valve 120 is provided on the valve body 110. The oil inlet of the shuttle valve 120 is connected to the regulating oil passage, and the oil outlet of the shuttle valve 120 is connected to the load sensing oil passage 1s. That is, the oil in the working chamber enters the shuttle valve 120 through the regulating oil passage, and after passing through the shuttle valve 120, it flows to the switching valve 200 and the compensator 104 of the steering pump 103 respectively.

[0063] In this embodiment, the oil inlet of the switching valve 200 is connected to the first oil inlet P, and the oil outlet of the switching valve 200 is connected to the working valve group 300; the switching valve stem 201 is provided with a first oil passage rsi and a second oil passage rst, the oil inlet of the switching valve 200 is connected to the oil outlet of the switching valve 200 through the first oil passage rsi, and the oil inlet of the switching valve 200 is connected to the return oil port T of the switching valve 200 through the second oil passage rst. Optionally, one end of the switching valve stem 201 is provided with a first elastic element, which is located in the second chamber c1s. If the pressure difference between the first chamber cs1 and the second chamber c1s is less than or equal to the elastic force of the first elastic element, the switching valve stem 201 is in the first position, so that the oil inlet of the switching valve 200 is connected to the oil outlet of the switching valve 200 through the first oil passage rsi. If the pressure difference between the first chamber cs1 and the second chamber c1s is greater than the elastic force of the first elastic element, the switching valve stem 201 moves to the second position, so that the oil inlet of the switching valve 200 is connected to the oil return port T of the switching valve 200 through the second oil passage rst.

[0064] The control chamber of the working valve assembly 300 is equipped with a second elastic element, which is connected to the working valve stem to position the working valve stem in either the third or fourth position. The working valve stem has a first channel, a second channel, a third channel, and a fourth channel. The working valve assembly 300 has a first working chamber and a second working chamber, which are respectively connected to the execution module. It can be understood that when the working valve stem is in the third position, the oil inlet of the working valve assembly 300 is connected to the first working chamber via the first channel, and the second working chamber is connected to the return port T via the fourth channel. When the working valve stem is in the fourth position, the oil inlet of the working valve assembly 300 is connected to the second working chamber via the third channel, and the first working chamber is connected to the return port T via the second channel.

[0065] The regulating oil passage includes a first damping hole, a second damping hole and an internal oil passage located on the working valve stem. The first damping hole is connected to the first working chamber, the second damping hole is connected to the second working chamber, and the first and second damping holes are respectively connected to the internal oil passage. The internal oil passage is connected to the load sensing oil port LS via the shuttle valve 120.

[0066] It is understood that the multi-way valve 100 can be applied to loaders to realize hydraulic control of the boom and bucket. That is, the number of control valves in the working valve group 300 includes two. In other application scenarios, the number of control valves in the working valve group 300 can also be one, three, four or more, and no specific limitation is made here. In this embodiment, the working valve group 300 including the boom control valve 310 and the bucket control valve 350 is used as an example for illustration.

[0067] Combination Figures 4 to 9 The first oil inlet P is connected to the boom control valve 310 and the bucket control valve 350 via a switching valve 200. The second oil inlet EF is also connected to both the boom control valve 310 and the bucket control valve 350. The working valve stem includes a boom valve stem 320 and a bucket valve stem 360. The boom valve stem 320 is movably mounted on the boom control valve 310, and the bucket valve stem 360 is movably mounted on the bucket control valve 350. The pilot oil inlets include a first pilot oil inlet xA2, a second pilot oil inlet xB2, a third pilot oil inlet xA1, and a fourth pilot oil inlet xB1. One end of the boom valve stem 320 is connected to the first pilot oil inlet xA2, and the other end is connected to the second pilot oil inlet xB2. One end of the bucket valve stem 360 is connected to the third pilot oil inlet xA1, and the other end is connected to the fourth pilot oil inlet xB1. Optionally, the second elastic element includes a second spring 330 and a third spring 370. The second spring 330 is located at one end of the boom valve stem 320, which in this embodiment is disposed at... Figure 6 From the right end of the view shown, the third spring 370 is located at one end of the bucket valve rod 360; in this embodiment, it is located at... Figure 6 The right end of the view shown.

[0068] Combination Figure 6 and Figure 14 The valve body 110 is provided with a first return oil passage T0 and a second return oil passage T1. The first return oil passage T0 is located on the right side of the valve body 110 and is connected to the return oil port T. The second return oil passage T1 is located on the left side of the valve body 110. The valve body 110 is provided with a back pressure valve 410, and the second return oil passage T1 is connected to the first return oil passage T0 through the back pressure valve 410.

[0069] It is understood that the control chamber of the working valve group 300 includes the left and right chambers of the boom valve stem 320 and the left and right chambers of the bucket valve stem 360. The left and right chambers of the boom valve stem 320 are connected to the first pilot inlet xA2 and the second pilot inlet xB2, respectively, and the left and right chambers of the bucket valve stem 360 are connected to the third pilot inlet xA1 and the fourth pilot inlet xB1, respectively.

[0070] In this embodiment, the valve body 110 is provided with a first check valve 420, a second check valve 430, and a third check valve 440. The inlet of the first check valve 420 is connected to the oil outlet of the switching valve 200, and the outlet of the first check valve 420 is connected to the working valve group 300. The valve body 110 is provided with oil passages EF, P1, P2, P3, and P4. One end of oil passage EF is connected to the second oil inlet EF, and the other end is connected to oil passage P2. Oil passage P2 is connected to oil passages P1, P3, and P4 respectively. Oil passage P1 is connected to the switching valve 200, oil passage P3 is connected to the boom control valve 310, and oil passage P4 is connected to the bucket control valve 350. Optionally, the first oil inlet P enters oil passage P1 via the first oil passage rsi of the switching valve 200. Oil passage P1 enters oil passage P2 via the first check valve 420. Oil passage P2 enters oil passage P3 via the second check valve 430. Oil passage P4 enters oil passage P4 via the third check valve 440. Oil passages P3 and P4 are respectively connected to the oil inlet of the working valve.

[0071] The left side of the switching valve stem 201 is the first chamber CS1, which is connected to oil passage P2 via an oil passage; the right side of the switching valve stem 201 is the second chamber C1s, which is connected to the load sensing oil passage LS via an oil passage.

[0072] A relief valve 160 is provided on the valve body 110. The high-pressure chamber rp of the relief valve 160 is connected to the load sensing oil passage ls, and the return port T of the relief valve 160 is connected to the first return oil passage T0. If the pressure in the load sensing oil passage ls is higher than the pressure set by the relief valve 160, the hydraulic oil in the load sensing oil passage ls is depressurized through the relief valve 160, resulting in a lower oil pressure in the second chamber c1s. The switching valve rod 201 moves, causing the switching valve 200 to be in the cut-off state, and the working pump 101 is unloaded, realizing high-pressure, low-flow operation of the boom cylinder and achieving energy saving in the hydraulic system.

[0073] In the boom control valve 310, the first working chamber includes a boom raising chamber bl, which is used to connect with the large chamber of the boom cylinder 301; the second working chamber includes a boom lowering chamber bd, which is used to connect with the small chamber of the boom cylinder 301; the boom valve stem 320 is provided with a first channel, a second channel, a third channel and a fourth channel, namely oil passages rb1, tb2, rbd and tb1. The boom raising chamber bl is connected to the oil port A2 of the large chamber of the boom cylinder 301, and the boom lowering chamber bd is connected to the oil port B2 of the small chamber of the boom cylinder 301.

[0074] In this embodiment, hydraulic fluid enters the right side of the boom valve stem 320 from the first pilot inlet xA2, controlling the boom valve stem 320 to move to the left. The boom lifting chamber bl of the boom control valve 310 is in the working position. Hydraulic fluid from the steering pump 103 enters the boom control valve 310 through the second inlet EF, and then enters the large chamber of the boom cylinder 301 through the boom lifting chamber bl, controlling the boom lifting. Specifically, oil passage P3 is connected to the boom lifting chamber bl via oil passage rb1, and the boom lowering chamber bd is connected to the first return oil passage T0 via oil passage tb2, realizing the lifting of the loader's boom cylinder.

[0075] Oil enters the left side of the boom valve stem 320 through the second pilot inlet xB2, controlling the boom valve stem 320 to move to the right. The boom lowering chamber bd of the boom control valve 310 is in the working position. Oil from the steering pump 103 enters the boom control valve 310 through the second inlet EF, and then enters the small chamber of the boom cylinder 301 through the boom lowering chamber bd, controlling the boom to lower. Specifically, oil passage P3 is connected to the boom lowering chamber bd via oil passage rbd, and the boom raising chamber bl is connected to the second return oil passage T1 via oil passage tb1, realizing the lowering of the loader's boom cylinder.

[0076] Similarly, in the bucket control valve 350, the first working chamber includes a bucket collecting chamber bkl, which is used to connect with the large chamber of the bucket cylinder 303; the second working chamber includes a bucket discharging chamber bkd, which is used to connect with the small chamber of the bucket cylinder 303; the return oil of the bucket collecting chamber bkl is connected to the second return oil passage T1, and the return oil of the bucket discharging chamber bkd is connected to the first return oil passage T0.

[0077] The bucket valve stem 360 is provided with a first channel, a second channel, a third channel, and a fourth channel, namely oil passages rbk1, rbk2, rbkd, and tbk1. The bucket collecting chamber bkl is connected to the large chamber oil port A1 of the bucket cylinder 303, and the bucket unloading chamber bkd is connected to the small chamber oil port B1 of the bucket cylinder 303. In this embodiment, the oil enters the right side of the bucket valve stem 360 from the third pilot oil inlet xA1, controlling the bucket valve stem 360 to move to the left. The bucket collecting chamber bkl of the bucket control valve 350 is in the working position. The oil from the steering pump 103 enters the oil passage P2 through the second oil inlet EF, enters the oil passage P4 through the third check valve 440, and enters the large chamber of the bucket cylinder 303 through the bucket collecting chamber bkl of the bucket control valve 350, controlling the bucket collecting. Specifically, oil passage P4 is connected to bucket recovery chamber bkl via oil passage rbk1, and bucket unloading chamber bkd is connected to first return oil passage T0 via oil passage rbk2, thus realizing bucket recovery of the loader.

[0078] Oil enters the left side of the bucket valve stem 360 through the fourth pilot inlet xB1, controlling the bucket valve stem 360 to move to the right. The bucket discharge chamber bkd of the bucket control valve 350 is in the working position. Oil from the steering pump 103 enters oil passage P2 through the second inlet EF, then enters oil passage P4 through the third check valve 440, and finally enters the small chamber of the bucket cylinder 303 through the bucket discharge chamber bkd of the bucket control valve 350, controlling the bucket discharge. Specifically, oil passage P4 is connected to the bucket discharge chamber bkd via oil passage rbkd, and the bucket receiving chamber bkl is connected to the second return oil passage T1 via oil passage tbk1, realizing the loader's bucket discharge.

[0079] A shuttle valve 120 is provided on the valve body 110. The shuttle valve 120 has a first oil port, a second oil port, and a third oil port. The first oil port is connected to the regulating oil passage on the boom valve stem 320, the second oil port is connected to the regulating oil passage on the bucket valve stem 360, and the third oil port is connected to the load sensing oil port LS. Optionally, the first damping hole and the second damping hole on the boom valve stem 320 are oil ports lsb1 and lsbr, respectively. The boom valve stem 320 is also provided with an oil port lsb, an oil passage lsb3, and an oil passage lsbt. Oil ports lsb1 and lsbr are connected to oil port lsb through the internal oil passage of the boom valve stem 320, enter the first oil port of the shuttle valve 120 through lsb3, and are connected to the load sensing oil passage ls through the third oil port of the shuttle valve 120. Oil port lsb is connected to the first return oil passage T0 through oil passages lsb3 and lsbt. That is, under normal (non-working) conditions, the oil in the load sensing oil port LS is connected to the first return oil passage T0.

[0080] The first and second damping holes on the bucket valve stem 360 are oil ports lsbk1 and lsbkr, respectively. The bucket valve stem 360 also has an oil port lsbk, an oil passage lsbk3, and an oil passage lsbkt. Oil ports lsbk1 and lsbkr are connected to oil port lsbk via the internal oil passage of the bucket valve stem 360, and then enter the second oil port of the shuttle valve 120 via oil passage lsb3. The oil then connects to the load sensing oil passage ls via the third oil port of the shuttle valve 120. Oil port lsbk is connected to the first return oil passage T0 via oil passages lsbk3 and lsbkt. That is, under normal conditions (non-working state), the oil at the load sensing oil port LS is connected to the first return oil passage T0.

[0081] Optionally, the valve body 110 is equipped with a floating control valve 130, a floating replenishing valve 140, and a replenishing valve 141. The floating replenishing valve 140 and the replenishing valve 141 are used to replenish oil to the small chamber of the working cylinder. It can be understood that during the bucket unloading process, a vacuum occurs in the small chamber of the bucket cylinder 303. The bucket unloading chamber bkd is connected to the small chamber of the bucket cylinder 303 and is below atmospheric pressure. The hydraulic oil in the large chamber of the bucket cylinder 303 returns to the second return oil passage T1 via the bucket receiving chamber bkl, the bucket valve rod 360, and the oil passage tbkl. Due to the back pressure PT1 generated by the back pressure valve 410, the return oil in the second return oil passage T1 pushes open the valve core of the replenishing valve 141 and enters the bucket unloading chamber bkd, thus preventing a vacuum from occurring in the small chamber of the bucket cylinder 303 and burning the seals.

[0082] Similarly, when the boom descends, a vacuum occurs in the small chamber of the boom cylinder 301. The boom descending chamber bd is connected to the small chamber of the boom cylinder 301 and is below atmospheric pressure. The hydraulic oil in the large chamber of the boom cylinder 301 returns to the second return oil passage T1 via the boom rising chamber bl, the boom valve stem 320, and the oil passage tbl. Due to the back pressure PT1 generated by the back pressure valve 410, the return oil in the second return oil passage T1 pushes open the valve core of the floating replenishing valve 140 and enters the boom descending chamber bd, thus preventing a vacuum from occurring in the small chamber of the boom cylinder 301 and burning the seals.

[0083] Optionally, the floating control valve 130 is connected to the floating replenishing valve 140. When the floating control valve 130 is working, the floating replenishing valve 140 has a floating function and can be used to keep the boom in a floating state during the boom descent process. When the floating control valve 130 is not working, the floating replenishing valve 140 can play a replenishing role, replenishing oil to the small chamber of the boom cylinder 301.

[0084] Optionally, the valve body 110 is also provided with a main safety valve 170. The high-pressure end of the main safety valve 170 is connected to the oil passage P2, and the other end is connected to the first return oil passage T0 to prevent the system pressure from being too high. The pressure value set by the main safety valve 170 is higher than the pressure value set by the relief valve 160.

[0085] The working principle of the multi-way valve 100 provided in this embodiment is as follows:

[0086] First operating condition: The engine is not started, and the working pump 101 and steering pump 103 are not working. The boom valve stem 320 is in the neutral position under the action of the second spring 330, and the boom control valve 310 is in the closed state. The bucket valve stem 360 is in the neutral position under the action of the third spring 370, and the bucket control valve 350 is in the closed state. The switching valve stem 201 is in the left position, i.e., the open state, under the action of the first spring 203.

[0087] The second operating condition: After the engine starts, the steering system is not operated; the pilot valve 105 is not operated, and the boom valve stem 320 and bucket valve stem 360 are in the neutral position; the oil from the steering pump 103 enters the second inlet EF of the multi-way valve 100 through the priority valve 106, enters the oil passage P2 through the oil passage EF, enters the oil passage P3 through the second check valve 430, and enters the oil passage P4 through the third check valve 440. At this time, the LS oil port is connected to the first return oil passage T0. Under the control of the built-in regulator, the steering pump 103 enters the fully hydraulic steering gear 401 through the load sensing oil passage ls of the priority valve 106 at the minimum pressure and minimum flow rate of 0.5~2L / min set by the regulator, and returns the oil through the return oil pipe of the steering gear 401, thus achieving energy saving. Optionally, the regulator's set pressure is generally 16 to 24 bar. This pressure simultaneously pushes the switching valve stem 201 to the right, and the switching valve 200 is in the closed state. The oil from the working pump 101 enters the first return oil passage T0 through the second oil passage rst and is unloaded at low pressure.

[0088] The third operating condition: After the engine starts, the steering system is not operated; the pilot valve 105 is operated, such as by operating the boom control lever to raise the boom. The first pilot inlet xA2 enters the pilot oil, controlling the boom valve stem 320 to move to the left. The oil from the steering pump 103 enters the P3 oil passage, and through the oil passage rbl, it enters the boom raising chamber bl, that is, the large chamber of the boom cylinder 301. The hydraulic oil in the small chamber of the boom cylinder 301 enters the boom lowering chamber bd of the boom control valve 310, and through the oil passage tb2, it connects with the first return oil passage T0 to return oil. At the same time, due to the movement of the boom valve stem 320, the oil passage lsbt is closed. Due to the weight of the boom, bucket, and material, the pressure oil in the boom raising chamber bl enters the internal oil passage of the boom valve stem 320 through the oil port lsb1 on the left side of the boom valve stem 320, and through the oil port lsb, oil passage lsb3, and shuttle valve 120, it enters the load sensing oil passage ls.

[0089] A portion of the pressurized oil entering the load sensing oil passage ls connects to the system shuttle valve 109 via the load sensing oil port LS, and acts on the spring chamber of the compensator 104 of the steering pump 103 via the x oil passage, increasing the displacement of the steering pump 103 to meet the flow requirements of the hydraulic system of the actuator module. The steering pump 103 can be a variable displacement piston pump, which provides even greater pressure.

[0090] The pressure oil entering the load sensing oil passage ls has a portion entering the second chamber c1s of the switching valve 200. The first spring 203 acts on the right side of the switching valve stem 201. ΔPbl is set as the pressure difference between oil passage P3 and boom lifting chamber bl. When the pressure ΔPbl is less than or equal to the elastic force of the first spring 203, the switching valve stem 201 is on the left side, the switching valve 200 is open, and the oil from the working pump 101 enters oil passage P1 through the first oil passage rsi, opens the first check valve 420 to enter P2, and opens the second check valve 430 to enter oil passage P3. In other words, the switching valve stem 201 controls the working pump 101 to merge with the hydraulic system of the execution module to accelerate the boom lifting of the execution module.

[0091] When the operator controls the boom lifting state in micro-motion mode, the pressure ΔPbl is greater than the elastic force of the first spring 203, pushing the switching valve rod 201 to the right side, the switching valve 200 is closed, and the oil from the working pump 101 enters the first return oil passage T0 through the second oil passage rst to return oil. That is, the switching valve rod 201 controls the working pump 101 to unload, thereby achieving energy saving in the hydraulic system.

[0092] During boom lifting, if the pressure oil in the boom rising chamber bl is higher than the set pressure of the relief valve 160 and is unloaded, the hydraulic oil pressure in the second chamber c1s of the switching valve 200 decreases. Under the action of the high pressure oil in the first chamber cs1, the switching valve rod 201 is pushed to the right, the switching valve 200 closes, and the working pump 101 is unloaded, thus realizing energy saving of the hydraulic system when the boom cylinder 301 is operating under high pressure and low flow.

[0093] Similarly, after the engine starts, the steering system is not operated; the pilot valve 105 is operated. If the boom control lever is lowered, pilot oil enters through the second pilot inlet xB2, controlling the boom valve stem 320 to move to the right. The oil from the steering pump 103 enters the P4 oil passage, and through the oil passage rbd, it enters the boom rising chamber bl, i.e., the small chamber of the boom cylinder 301. The hydraulic oil in the large chamber of the boom cylinder 301 enters the boom rising chamber bl of the boom control valve 310, and through the oil passage tb1, it connects with the second return oil passage T1 for return oil. At the same time, due to the movement of the boom valve stem 320, the oil passage lsbt is closed. Due to the weight of the boom, bucket, and material, the pressure oil in the boom lowering chamber bl enters the internal oil passage of the boom valve stem 320 through the oil port lsbr on the right side of the boom valve stem 320, and through the oil port lsb, oil passage lsb3, and shuttle valve 120, it enters the load sensing oil passage ls.

[0094] A portion of the pressurized oil entering the load sensing oil passage ls is connected to the system shuttle valve 109 via the load sensing oil port LS, and acts on the spring chamber of the compensator 104 of the steering pump 103 through the x oil passage, increasing the displacement of the steering pump 103 to meet the flow requirements of the hydraulic system of the actuator module.

[0095] The pressure oil entering the load sensing oil passage ls has a portion entering the second chamber c1s of the switching valve 200. The first spring 203 acts on the right side of the switching valve stem 201. ΔPbl is set as the pressure difference between oil passage P3 and boom lifting chamber bl. When the pressure ΔPbl is less than or equal to the elastic force of the first spring 203, the switching valve stem 201 is on the left side, the switching valve 200 is open, and the oil from the working pump 101 enters oil passage P1 through the first oil passage rsi, opens the first check valve 420 to enter P2, and opens the second check valve 430 to enter oil passage P3. In other words, the switching valve stem 201 controls the working pump 101 to merge with the hydraulic system of the execution module to accelerate the boom descent of the execution module.

[0096] When the operator controls the boom to descend using micro-motion, the pressure ΔPbl is greater than the elastic force of the first spring 203, pushing the switching valve rod 201 to the right, closing the switching valve 200, and the oil from the working pump 101 enters the first return oil passage T0 through the second oil passage rst. In other words, the switching valve rod 201 controls the working pump 101 to unload, thereby achieving energy saving in the hydraulic system.

[0097] During boom descent, if the pressure oil in the boom descent chamber bd is higher than the set pressure of the relief valve 160 and is unloaded, the hydraulic oil pressure in the second chamber c1s of the switching valve 200 decreases. Under the action of the high-pressure oil in the second chamber c1s, the switching valve rod 201 is pushed to the right, the switching valve 200 closes, and the working pump 101 is unloaded, thus achieving energy saving in the hydraulic system when the boom cylinder 301 is operating under high pressure and low flow.

[0098] When the execution module descends, a vacuum appears in the small chamber of the boom cylinder. The boom lowering chamber bd is connected to the small chamber of the boom cylinder 301, and the pressure is lower than atmospheric pressure. The hydraulic oil in the large chamber of the boom cylinder 301 returns to the second return oil passage T1 through the boom rising chamber bl, the boom valve stem 320, and the oil passage tbl. Due to the back pressure PT1 generated by the back pressure valve 410, the return oil in the second return oil passage T1 pushes open the valve core and enters the boom lowering chamber bd for oil replenishment, thus preventing a vacuum from appearing in the small chamber of the boom cylinder 301 and burning the seals.

[0099] The fourth operating condition: After the engine starts, the steering system is not operated; the pilot valve 105 is operated, such as by operating the bucket retractor lever, the third pilot oil inlet xA1 enters the pilot oil, controlling the bucket valve lever 360 to move to the left, the oil of the steering pump 103 enters the P4 oil passage, and enters the bucket retractor chamber bkl through the oil passage rbkl, that is, the large chamber oil inlet of the bucket cylinder 303; the hydraulic oil in the small chamber of the bucket cylinder 303 enters the bucket unloading chamber bkd, and returns oil through the oil passage Tbk2 and connects with the first return oil passage T0. At the same time, due to the movement of the bucket valve lever 360, the oil passage lsbkt is closed. Due to the load on the bucket retractor, the pressure oil in the bucket retractor chamber bkl enters the internal channel of the bucket valve lever 360 through the oil port lsbk1 on the left side of the bucket valve lever 360, and enters the load sensing oil passage ls through the oil port lsbk, the oil passage lsbk3, and the shuttle valve 120. The pressurized oil is connected to the system shuttle valve 109 via the load sensing port LS on one side, and acts on the spring chamber of the compensator 104 of the steering pump 103 through the system x oil passage, increasing the displacement of the steering pump 103 to meet the flow requirements of the hydraulic system of the execution module. The pressurized oil enters the second chamber c1s of the switching valve 200 on the other side, and acts together with the first spring 203 on the right side of the switching valve stem 201. ΔPbk1 is set as the pressure difference between oil passage P4 and bucket turning and collecting chamber bkl. When the pressure ΔPbkl is less than or equal to the elastic force of the first spring 203, the switching valve stem 201 is on the left side, the switching valve 200 is open, and the oil from the working pump 101 enters oil passage P1 through the first oil passage rsi, opens the first check valve 420 to enter P2, and enters oil passage P4 through the third check valve 440. That is, the switching valve stem 201 controls the working pump 101 to merge with the hydraulic system of the execution module to accelerate the bucket turning and collecting of the execution module.

[0100] When the operator controls the bucket retraction state using micro-motion, the pressure ΔPbkl is greater than the elastic force of the first spring 203, pushing the switching valve rod 201 to the right side, closing the switching valve 200, and the oil from the working pump 101 enters the first return oil passage T0 through the second oil passage rst. That is, the switching valve rod 201 controls the working pump 101 to unload, thereby achieving energy saving in the hydraulic system.

[0101] If the pressure oil in the bucket retraction chamber bk1 is higher than the set pressure of the relief valve 160 and is unloaded, the hydraulic oil pressure in the second chamber c1s of the switching valve 200 decreases. Under the action of the high pressure oil in the first chamber CS1, the switching valve rod 201 is pushed to the right, the switching valve 200 closes, the working pump 101 is unloaded, and the bucket cylinder can operate under high pressure and low flow, thus achieving energy saving in the hydraulic system.

[0102] It should be noted that after the engine starts, the steering system is not operated; the pilot valve 105 is operated, such as when the bucket is turned to unload, the fourth pilot oil inlet xB1 enters the pilot oil, and its control principle is similar to that described above, so it will not be described in detail here. It should also be noted that when the bucket of the actuator module is turning to unload, a vacuum occurs in the small cavity of the bucket cylinder 303. The oil replenishing valve 141 can replenish oil to the small cavity of the bucket cylinder 303. The oil replenishing principle is similar to the oil replenishing principle of the small cavity of the boom cylinder 301, which avoids the vacuum in the small cavity of the bucket cylinder 303 from burning the seals.

[0103] Furthermore, during boom descent, the floating control valve 130 and the floating replenishing valve 140 allow the actuator module to float, with a floating control pressure set at 25–30 bar. The floating replenishing valve 140 also reduces the sinking of the boom cylinder 301. During boom descent, the rapid descent valve allows the boom cylinder 301 of the actuator module to directly return oil, achieving rapid descent. This is suitable for the hydraulic control system of large loaders, improving operational efficiency.

[0104] Optionally, the multi-way valve 100 also includes a pressure reducing valve 460, which is disposed on the control oil line between the pilot inlet and the control chamber. In this embodiment, the pressure reducing valve 460 is disposed on the control oil line between the third pilot inlet xA1 and the large chamber of the bucket cylinder 303, enabling combined operation of the boom and the bucket, resulting in a high bucket filling rate and thus high operating efficiency, greatly reducing the operator's workload. In this embodiment, the pressure reducing valve 460 is disposed in the control end cover of the large chamber of the bucket, resulting in a compact structure.

[0105] It should be noted that the switching valve stem 201 in this embodiment is automatically controlled by the hydraulic system. In other optional embodiments, the switching valve 200 can also be opened and closed by external electrical control or external hydraulic control to achieve the confluence and unloading of the working pump 101. The spatial relationship of the switching valve stem 201, boom valve stem 320, bucket valve stem 360, relief valve 160, floating replenishing valve 140, floating control valve 130, replenishing valve 141, shuttle valve 120, rapid descent valve, etc. in this embodiment can be flexibly set and arranged according to actual needs, as long as the oil circuit is connected according to the principle conceived in this application. No specific limitation is made here. The schematic diagram of the hydraulic system control principle only shows the oil circuit connection principle and is not intended to limit the position of each hydraulic component. Figure 1 The pilot valve 105, pilot oil source valve and brake valve shown in the figure adopt existing structures and are not improvements of this application, so they will not be described in detail.

[0106] This embodiment also provides a hydraulic system, including a working pump 101, a steering pump 103, an actuator module, and the aforementioned multi-way valve 100. The working pump 101 and steering pump 103 are respectively connected to the multi-way valve 100, which is connected to the actuator module. This system is suitable for construction machinery such as loaders. It enables the working pump 101 to automatically unload or merge flow when the actuator module is in a micro-motion or full-speed motion state, optimizing flow distribution and achieving energy savings in the hydraulic system. Furthermore, it allows the hydraulic system to operate at high pressure and low flow rate, and at low pressure and high flow rate, resulting in significant energy savings.

[0107] In summary, the embodiments of the present invention provide a multi-way valve 100 and a hydraulic system, which have the following beneficial effects:

[0108] The multi-way valve 100 integrates the switching valve 200 onto the valve body 110, enabling automatic unloading or merging of the working pump 101 during micro-motion and full-speed operation of the actuator module. This optimizes flow distribution and achieves energy savings in the hydraulic system. It also allows for high-pressure, low-flow operation and low-pressure, high-flow operation, resulting in significant energy savings. The integrated arrangement of the floating replenishing valve 140, floating control valve 130, and replenishing valve 141 reduces piping, leakage, and settlement. The rapid descent valve enables rapid boom descent, suitable for hydraulic control systems of large loaders, improving operational efficiency. The overall structure is compact, low-cost, and highly energy-efficient.

[0109] The hydraulic system provided in this invention is suitable for construction machinery such as loaders. It can automatically unload or merge the working pump 101 when the actuator is in a micro-motion state or a full-speed motion state, optimizing the flow distribution and achieving energy saving in the hydraulic system. Furthermore, it can achieve high-pressure, low-flow operation and low-pressure, high-flow operation in the hydraulic system, resulting in significant energy savings.

[0110] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-way valve, characterized in that, It includes a valve body and a switching valve and a working valve assembly disposed on the valve body. The valve body is provided with a first oil inlet (P) and a second oil inlet (EF). The first oil inlet (P) is used to communicate with the working pump, and the second oil inlet (EF) is used to communicate with the steering pump. The switching valve is provided with a switching valve stem, a first chamber and a second chamber, and the switching valve stem can move in the first chamber and the second chamber; the working valve group is provided with a working valve inlet, which is connected to the first chamber; the valve body is provided with a load sensing oil passage (1s), which is connected to the second chamber. The valve body is provided with a return port (T), the working valve inlet is connected to the first inlet (P) and the second inlet (EF) respectively, the switching valve inlet is connected to the first inlet (P), the switching valve outlet is connected to the working valve group, and the switching valve return port is connected to the return port (T). If the pressure difference between the working valve inlet and the second chamber is less than or equal to a first preset value, the switching valve stem is in a first position to connect the oil passage between the first inlet (P) and the working valve inlet, and the oil from the working pump flows through the switching valve to the working valve assembly to merge with the oil output from the steering pump; if the pressure difference between the working valve inlet and the second chamber is greater than the first preset value, the switching valve stem is in a second position to cut off the oil passage between the first inlet (P) and the working valve inlet, and the oil from the working pump flows back to the oil tank after passing through the switching valve; The valve body is equipped with a relief valve. The high-pressure chamber of the relief valve is connected to the load sensing oil passage (1s), and the return port of the relief valve is connected to the return port (T). If the pressure of the load sensing oil passage (1s) is higher than the pressure set by the relief valve, the hydraulic oil in the load sensing oil passage (1s) is depressurized through the relief valve, and the valve stem is switched to the second position. The valve body is equipped with a pilot oil inlet, a pressure reducing valve, a floating control valve, a floating replenishing valve, a replenishing valve, and a second return oil passage (T1). The working valve assembly includes a bucket valve stem, and the pilot inlet includes a third pilot inlet (xA1) and a fourth pilot inlet (xB1). One end of the bucket valve stem is connected to the third pilot inlet (xA1), and the other end is connected to the fourth pilot inlet (xB1). A pressure reducing valve is installed on the control oil line between the third pilot inlet (xA1) and the large chamber of the bucket cylinder, and the pressure reducing valve is installed in the control end cover of the large chamber of the bucket cylinder. One end of the replenishing oil valve is connected to the second return oil passage (T1), and the other end is connected to the bucket discharge chamber (bkd); one end of the floating replenishing oil valve is connected to the second return oil passage (T1), and the other end is connected to the boom lowering chamber (bd); the floating replenishing oil valve and the replenishing oil valve are used to replenish oil to the small chamber of the working cylinder; The floating control valve is connected to the floating replenishing valve. When the floating control valve is working, the floating replenishing valve has a floating function and can be used to keep the boom in a floating state during the boom descent process. When the floating control valve is not working, the floating replenishing valve can replenish oil to the small chamber of the boom cylinder.

2. The multi-way valve according to claim 1, characterized in that, The valve body is provided with a load sensing port (LS), the pilot inlet is used to communicate with the pilot valve, and the return port (T) and the load sensing port (LS) are respectively connected to the oil tank. The working valve assembly is provided with a control chamber, a working chamber, and a working valve stem. The pilot oil inlet is connected to the control chamber. Pilot oil enters the control chamber from the pilot oil inlet. The pilot oil is used to drive the working valve stem to move so that the working valve inlet is connected to the working chamber. The working chamber is used to connect to the execution module.

3. The multi-way valve according to claim 2, characterized in that, The switching valve stem is provided with a first oil passage (rsi) and a second oil passage (rst). The oil inlet of the switching valve is connected to the oil outlet of the switching valve through the first oil passage (rsi), and the oil inlet of the switching valve is connected to the oil return port of the switching valve through the second oil passage (rst).

4. The multi-way valve according to claim 3, characterized in that, One end of the switching valve stem is provided with a first elastic element, which is located in the second chamber. If the pressure difference between the first chamber and the second chamber is less than or equal to the elastic force of the first elastic element, the switching valve stem is in a first position, so that the oil inlet of the switching valve is connected to the oil outlet of the switching valve through the first oil passage (rsi). If the pressure difference between the first chamber and the second chamber is greater than the elastic force of the first elastic element, the switching valve stem moves to a second position, so that the oil inlet of the switching valve is connected to the oil return port of the switching valve through the second oil passage (rst).

5. The multi-way valve according to claim 2, characterized in that, The control chamber is provided with a second elastic element, which is connected to the working valve stem so that the working valve stem is in a third or fourth position. The working valve stem is provided with a first channel, a second channel, a third channel and a fourth channel, and the working valve group is provided with a first working chamber and a second working chamber, the first working chamber and the second working chamber being respectively connected to the execution module; The working valve stem is in the third position, the oil inlet of the working valve group is connected to the first working chamber through the first channel, and the second working chamber is connected to the oil return port through the fourth channel; The working valve stem is in the fourth position, the oil inlet of the working valve assembly is connected to the second working chamber through the third channel, and the first working chamber is connected to the oil return port through the second channel.

6. The multi-way valve according to claim 5, characterized in that, The working valve stem is provided with an adjusting oil passage, which includes a first damping hole, a second damping hole and an internal oil passage provided on the working valve stem. The first damping hole is connected to the first working chamber, the second damping hole is connected to the second working chamber, the first damping hole and the second damping hole are respectively connected to the internal oil passage, and the internal oil passage is connected to the load sensing oil port.

7. The multi-way valve according to claim 5, characterized in that, The working valve assembly includes a boom control valve and a bucket control valve. The first oil inlet (P) is connected to both the boom control valve and the bucket control valve via the switching valve, and the second oil inlet (EF) is connected to both the boom control valve and the bucket control valve. The working valve stem includes a boom valve stem and a bucket valve stem. The boom valve stem is movably mounted on the boom control valve, and the bucket valve stem is movably mounted on the bucket control valve. The pilot oil inlet includes a first pilot oil inlet, a second pilot oil inlet, a third pilot oil inlet, and a fourth pilot oil inlet. One end of the boom valve rod is connected to the first pilot oil inlet, and the other end is connected to the second pilot oil inlet. One end of the bucket valve rod is connected to the third pilot oil inlet, and the other end is connected to the fourth pilot oil inlet.

8. The multi-way valve according to claim 7, characterized in that, The valve body is provided with a first return oil passage (T0); the valve body is provided with a back pressure valve, and the second return oil passage (T1) is connected to the first return oil passage (T0) through the back pressure valve; In the boom control valve, the first working chamber includes a boom raising chamber for connection to the large chamber of the boom cylinder; the second working chamber includes a boom lowering chamber for connection to the small chamber of the boom cylinder; the return oil of the boom raising chamber is connected to the second return oil passage (T1), and the return oil of the boom lowering chamber is connected to the first return oil passage (T0); the first return oil passage (T0) is connected to the return oil port (T).

9. The multi-way valve according to claim 8, characterized in that, In the bucket control valve, the first working chamber includes a bucket collecting chamber for connecting to the large chamber of the bucket cylinder; the second working chamber includes a bucket discharging chamber for connecting to the small chamber of the bucket cylinder; the return oil of the bucket collecting chamber is connected to the second return oil passage (T1), and the return oil of the bucket discharging chamber is connected to the first return oil passage (T0).

10. The multi-way valve according to claim 7, characterized in that, The valve body is equipped with a shuttle valve, which has a first oil port, a second oil port and a third oil port. The first oil port is connected to the regulating oil passage on the boom valve rod, the second oil port is connected to the regulating oil passage on the bucket valve rod, and the third oil port is connected to the load sensing oil port.

11. A hydraulic system, characterized in that, It includes a working pump, a steering pump, an actuator module, and a multi-way valve as described in any one of claims 1 to 10, wherein the working pump and the steering pump are respectively connected to the multi-way valve, and the multi-way valve is connected to the actuator module.

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