Multi-way valve and hydraulic system for controlling sequential action

Abstract

The invention relates to the technical field of hydraulic pressure, in particular to a multi-way valve and a hydraulic system for controlling sequential actions. A multi-way valve is used for controlling sequential actions of at least two executive components and comprises at least two working units, the working units are arranged corresponding to the executive components, and each working unit comprises a control valve for controlling the corresponding executive component to act; the pilot valve is arranged aiming at the control valve, and the pilot valve controls pilot oil to enter and exit from the control valve; in an initial state, pilot oil can enter the control valve through the pilot valve, so that the control valve reverses to control the corresponding execution element to act; and after the corresponding execution element moves in place, the oil pressure of the oil inlet cavity is increased to trigger the pilot valve to reverse, and pilot oil flows out through the reversed pilot valve and is used as pilot oil of the working unit corresponding to the execution element for executing the next action. The technical problems that hydraulic elements and oil ways of a hydraulic system in the prior art are various and complex, and pressure loss is caused when oil passes through a sequence valve are solved.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, and in particular to a multi-way valve and a hydraulic system for controlling sequential actions. Background Art

[0002] In the prior art, for a hydraulic system controlled by a hydraulically controlled multi-way valve, a pilot signal usually controls a valve core of the multi-way valve to switch to one side, thereby outputting oil from the oil inlet of the multi-way valve to the corresponding working port.

[0003] like Figure 1 As shown, taking the two-way hydraulically controlled multi-way valve of an open-center system as an example, hydraulic pump 1' outputs oil to port P' of the multi-way valve. Pilot signals a1' and b1' control the direction of the first valve spool 2', while pilot signals a2' and b2' control the direction of the second valve spool 4'. After the pilot signal a1' is input to cause the first valve spool 2' to reverse, the oil in port P' passes through the first valve spool 2' and enters the small chamber of the first cylinder 3'. The large chamber of the first cylinder 3' then returns to port T' through the first valve spool 2' and to the tank. The remaining control logic is similar. To extend the first cylinder 3' and then the second cylinder 5', a pilot signal a1' is required. After the first cylinder 3' reaches the end of its stroke, the a1' pilot pressure is released. Then, a pilot signal a2' is input to release the a2' pressure after the second cylinder 5' reaches the end of its stroke, completing the movement. The above control process requires multiple control pilot signals, and the multiple pilot signals need to be given in sequence, which is cumbersome to operate and difficult to control.

[0004] In order to realize the sequential action of the control actuators, schemes for controlling the sequence of the control actuators have appeared in the prior art. For example, the document with application number CN201911071335.1 discloses a hydraulic system, method and engineering vehicle for realizing the sequential action of the engineering vehicle mechanism. This scheme controls the sequential action of the actuator by setting a sequence valve between the reversing valve and the actuator cylinder, and reversing the sequence valve by holding the pressure when the cylinder moves to the end of the stroke, thereby controlling the sequential action of the actuator. The three-position four-way solenoid reversing valve reverses to the left, first the locking cylinder small chamber is filled with oil, and after moving to the end of the stroke, the sequence valve II opens, and the lifting cylinder large chamber is filled with oil, and then moves to the end of the stroke. The three-position four-way solenoid reversing valve reverses to the right, first the lifting cylinder small chamber is filled with oil, and after moving to the end of the stroke, the sequence valve I opens, and the locking cylinder large chamber is filled with oil. This scheme controls the sequential action of the two actuators through the solenoid reversing valve and the external sequence valve.

[0005] For example, the document with application number CN201911400683.9 discloses a new hydraulic system with a mechanism to prevent disorder of sequential actions. This scheme closes the sequence valve by the return oil back pressure of the cylinder that moves first. After the cylinder that moves first moves to the end of its stroke, the return oil back pressure is zero, and the spring force causes the sequence valve to reverse, causing the cylinder that moves later to move. When the action starts in sequence 1 (the first cylinder retracts and the second cylinder extends), the electromagnet on the right side of the Y-type function three-position four-way solenoid reversing valve is energized, so that the P interface and B interface of the valve are connected, and the A interface and T interface are connected. The pressure oil P flows through the two-way hydraulic lock and enters the rod chamber of the first cylinder. At the same time, the rodless chamber oil flows through the pilot sequence valve group and the two-way hydraulic lock, and then returns to the oil tank through the passage from the A interface to the T interface of the Y-type function three-position four-way solenoid reversing valve, thereby driving the piston rod to retract and causing the first cylinder to retract. At this point, back pressure is generated in the return chamber of the first cylinder, driving the second logic valve into the disconnected state, disconnecting the pilot oil circuit of the pilot sequence valve group. The pilot sequence valve group is in the closed state, and the second cylinder will not operate. When the first cylinder retracts, the oil in the return chamber of the first cylinder stops flowing and no back pressure is generated. The second logic valve is in the connected state under the action of the spring force, connecting the pilot oil circuit of the pilot sequence valve group, opening the pilot sequence valve group, and the second cylinder begins to operate. The same process is carried out according to sequence 2 (second cylinder retracts, first cylinder extends).

[0006] The two aforementioned solutions can achieve sequential control of the movements of two actuators, but both require the addition of solenoid valves and multiple sequence valves. This increases the number of hydraulic system components and the complexity of the oil circuits, making adjustments to the sequence of actions difficult. During a sequence, the output fluid must pass through the sequence valves before being delivered to the cylinders. This causes pressure loss, reducing the efficiency of the hydraulic system. Summary of the Invention

[0007] In order to solve the technical problems in the prior art of hydraulic systems with numerous and complex hydraulic components and oil circuits, and the pressure loss caused by the oil passing through the sequential valve, the present invention provides a multi-way valve and a hydraulic system for controlling sequential actions, which solves the above technical problems.

[0008] In order to solve the above technical problems, the present invention provides a multi-way valve for controlling the sequential actions of at least two actuators, including at least two working links, the working links being arranged corresponding to the actuators, and the working links comprising:

[0009] A control valve, wherein the control valve controls the action of a corresponding actuator;

[0010] The pilot valve is set for the control valve, and the pilot valve controls the pilot oil in and out of the control valve; in the initial state, the pilot oil can enter the control valve through the pilot valve, so that the control valve switches to control the action of the corresponding actuator; after the corresponding actuator moves into place, the oil pressure in its oil inlet chamber increases, triggering the pilot valve to switch direction, and the pilot oil flows out through the switched pilot valve and is used as the pilot oil of the working link to control the action of the next actuator.

[0011] According to one embodiment of the present invention, after the pilot valve is switched, oil returns to the pilot chamber of the corresponding control valve.

[0012] According to one embodiment of the present invention, the switching pressure of the pilot valve is slightly greater than the maximum load pressure of the corresponding actuator.

[0013] According to one embodiment of the present invention, pilot cavities are formed at both ends of the control valve, and the pilot valve controls the pilot oil to flow in and out of one of the pilot cavities.

[0014] According to one embodiment of the present invention, the pilot valve includes an oil inlet, an oil return port, a working oil port and an oil outlet. The oil inlet introduces pilot oil, the oil return port is connected to the oil tank, the working oil port is connected to the pilot chamber of the corresponding control valve, and the oil outlet is connected to the oil inlet of the pilot valve of the working link corresponding to the next actuator. In the initial state, the oil inlet and the working oil port are connected, and the oil outlet and the oil return port are connected; after switching, the working oil port and the oil return port are connected, and the oil inlet and the oil outlet are connected.

[0015] According to one embodiment of the present invention, the working link includes a valve body, and the corresponding control valve and pilot valve are assembled in the valve body.

[0016] According to one embodiment of the present invention, the oil inlet and the oil outlet of the pilot valve both extend to the surface of the valve body, and the oil outlet of the pilot valve is connected to the oil inlet of the next pilot valve through an external pipeline.

[0017] According to one embodiment of the present invention, the valve body includes an intermediate valve body, end covers are provided at both ends of the intermediate valve body, the control valve is installed in the intermediate valve body, the two ends of the control valve extend into the end covers to form the pilot cavity, and the pilot valve is assembled on the end covers.

[0018] According to one embodiment of the present invention, all working links are stacked according to the action sequence of the actuators, and all pilot valves are located on the same side of the valve body.

[0019] According to one embodiment of the present invention, a neutral unloading oil passage is further included, and the neutral unloading oil passage passes through all the control valves.

[0020] The present invention also provides a hydraulic system for controlling sequential actions, comprising:

[0021] Oil source, providing pressure oil and pilot oil;

[0022] Multi-way valve, the pressure oil is supplied to each control valve, and the pilot oil is supplied to the pilot valve of the working link corresponding to the actuator performing the first action;

[0023] There are at least two actuators, and the actuators are connected to the control valves of the corresponding working links.

[0024] Based on the above technical solution, the technical effects that can be achieved by the present invention are:

[0025] 1. The multi-way valve of the present invention is provided with a working link corresponding to the actuator, and the direction of the pilot oil is controlled by the pilot valve. In the initial state, the pilot oil enters the pilot chamber of the corresponding control valve through the pilot valve, causing the corresponding control valve to change direction, and controlling the corresponding actuator to act first; when the corresponding actuator moves into place, the oil pressure in the oil inlet chamber of the actuator begins to increase, and the oil inlet chamber of the actuator is connected with the pilot pressure chamber of the pilot valve. The oil pressure in the oil inlet chamber triggers the reversal of the pilot valve. After the pilot valve is reversed, the pilot oil is controlled to no longer enter the corresponding control valve, but to flow out and be used as the pilot oil of the working link corresponding to the actuator that performs the next action. The pilot valve of the working link corresponding to the actuator that performs the next action repeats the working process of the previous pilot valve, controls the pilot oil source to enter the corresponding control valve, controls the corresponding actuator to act later, and so on, to realize the sequential action of all actuators. The multi-way valve of the present invention only adds a pilot valve structure to the existing multi-way valve, which can realize the sequential action of at least two actuators. Compared with the structure of the prior art that adds a solenoid valve and multiple sequence valves, the present invention has fewer hydraulic components, and the pressure oil does not need to pass through the pilot valve, which will not cause pressure loss, and the hydraulic system efficiency is high.

[0026] 2. The multi-way valve of the present invention is configured such that after the pilot valve is switched, the corresponding pilot chamber of the control valve returns oil. After the pilot valve is switched, the pilot chamber of the control valve is in a low-pressure state, and the control valve can automatically return to the neutral position. The pressure oil will no longer enter the actuator after the action is completed, thereby protecting the actuator.

[0027] 3. The multi-way valve of the present invention sets the switching pressure of the pilot valve so that the pilot valve will not switch direction during the operation of the corresponding actuator, ensuring that the actuator moves into position. The pilot valve will not be triggered to switch direction until the oil pressure in the oil inlet chamber continues to rise after the actuator moves into position.

[0028] 4. The multi-way valve of the present invention specifically sets the oil port and oil circuit of the pilot valve so that in the initial state, the pilot valve can control the pilot oil to enter the corresponding control valve. At the same time, the pilot chamber of the next control valve is connected to the return oil port through the two pilot valves and is in a low-pressure state, so that the next control valve is in the middle position; after the pilot valve is reversed, the pilot oil can be controlled to flow out and be used as the pilot oil of the next control valve, and the pilot chamber of the control valve of this connection is connected to the return oil port and is in a low-pressure state. That is, taking the working links corresponding to the two actuators that act sequentially as an example, in normal operation, in the initial state, the pilot valves of the two working links are both in the initial state, the pilot oil first reaches the preceding working link, enters the preceding control valve through the preceding pilot valve, and causes the preceding control valve to switch to the working position, the pressure oil enters the preceding actuator through the preceding control valve, and the preceding actuator acts first; when the preceding actuator is in place, its oil inlet chamber is still filled with oil and the oil pressure increases, the oil pressure in the oil inlet chamber triggers the preceding pilot valve to switch, the pilot oil flows through the preceding pilot valve after switching to the following pilot valve, and at the same time, the pilot chamber of the preceding control valve is connected to the oil return port, its pilot chamber is depressurized, the preceding control valve returns to the middle position, and the pressure oil will no longer impact the preceding actuator. The flow to the following pilot valve will repeat the action of the preceding pilot valve, and proceed in sequence, realizing the sequential action of at least two working links and controlling the sequential action of at least two actuators;

[0029] 5. In the multi-way valve of the present invention, each working link includes a valve body, into which the control valve and pilot valve are assembled, making it easy to adjust the number of working links and to assemble them. The oil inlet and outlet of the pilot valve extend to the surface of the valve body, facilitating communication between the pilot valves of the working links corresponding to the actuators that operate sequentially. When the number of actuators increases, only the corresponding number of working links need to be added. The pilot valves between the working links corresponding to adjacent actuators that operate sequentially can be connected via external pipes, making it easy to increase or decrease the number of actuators.

[0030] 6. The multi-way valve of the present invention has a valve body structure consisting of an intermediate valve body and end caps at both ends. The pilot valve is assembled on one end cap. The pilot chamber controlled by the pilot valve is easily adjustable, thereby adjusting the action of the corresponding actuator. For example, when the pilot valve controls the pilot chamber on one side of the control valve to flow oil, the actuator extends; when the pilot valve controls the pilot chamber on the other side of the control valve to flow oil, the actuator retracts. That is, by adjusting the position of the end cap where the pilot valve is located so that it acts on the corresponding pilot chamber, the actuator performs the desired action. This facilitates the realization of the desired sequential action and allows for flexible adjustment as needed.

[0031] 7. In the multi-way valve of the present invention, all working links are stacked according to the action sequence of the actuators, and all pilot valves are located on the same side of the valve body, which facilitates the assembly of external pipelines. The external pipelines are located on the same side of the multi-way valve, and there is no entanglement between the external pipelines.

[0032] 8. In the hydraulic system of the present invention, the pilot oil only needs to be supplied to the pilot valve of the working link corresponding to the actuator that performs the first action. When the pilot signal is issued, the pilot oil reaches the oil inlet of the pilot valve of the first working link, and begins to control the sequential action of at least two actuators. The entire process only requires one pilot signal control, which is convenient for operation and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a hydraulic principle diagram of a two-way hydraulically controlled valve in an open center system of the prior art;

[0034] Figure 2 This is a hydraulic principle diagram of a hydraulic system according to a first embodiment of the present invention;

[0035] Figure 3 This is the hydraulic principle diagram of the first working joint;

[0036] Figure 4 for Figure 3 A magnified view of part A;

[0037] Figure 5 for Figure 3 A magnified view of part B;

[0038] Figure 6 This is a structural schematic diagram of the first end cover of the first working unit equipped with a first pilot valve;

[0039] Figure 7 This is the hydraulic principle diagram of the second working joint;

[0040] Figure 8 for Figure 7 Magnified view of part C;

[0041] Figure 9 This is a hydraulic state diagram when the first pilot valve of the first working link controls the pilot oil to enter the first pilot chamber of the first control valve to cause the first control valve to switch direction;

[0042] Figure 10 This is a hydraulic state diagram of the first working link where the first pilot valve is switched under the oil pressure of the oil inlet chamber of the first actuator, and the pilot oil is delivered to the second pilot chamber of the second working link, and the first control valve returns to the neutral position;

[0043] Figure 11 This is a hydraulic principle diagram of a hydraulic system according to a second embodiment of the present invention;

[0044] Figure 12 for Figure 11 An enlarged view of the D portion;

[0045] Figure 13The hydraulic principle diagram of the hydraulic system including four working links;

[0046] Figure 14 This is a hydraulic principle diagram of a hydraulic system according to a third embodiment of the present invention;

[0047] In the figure: 10-multi-way valve; 1-first working joint; 11-first control valve; 111-first pilot chamber; 12-first pilot valve; 121-first pilot valve spool; 122-first spring; 123-first adjusting screw; 13-first oil circuit; 14-first valve body; 141-first intermediate valve body; 142-first end cover; 2-second working joint; 21-second control valve; 22-second pilot valve; 23-second oil circuit; 3-third working joint; 31-third control valve; 32-third pilot valve; 33-third oil circuit; 4-fourth working joint; 41-fourth control valve; 42-fourth pilot valve; 43-fourth oil circuit; 5-safety joint; 51-safety valve; 6-mid-position unloading oil passage; 7-external pipeline;

[0048] 20-actuator; 201-first actuator; 202-second actuator; 203-third actuator; 204-fourth actuator;

[0049] 30-pressure oil source;

[0050] 40-fuel tank;

[0051] 1'-hydraulic pump; 2'-first valve core; 3'-first oil cylinder; 4'-second valve core; 5'-second oil cylinder. DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0055] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0056] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0057] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] like Figure 2-10 As shown, this embodiment provides a multi-way valve 10 for controlling the sequential actions of at least two actuators 20 . The multi-way valve 10 includes at least two working links, each of which controls the operation of one actuator 20 .

[0060] The working link includes a control valve and a pilot valve. The control valve controls the action of the corresponding actuator 20. The pilot valve is set for the control valve. The pilot valve controls the pilot oil in and out of the control valve. In the initial state, the pilot oil can enter the control valve through the pilot valve, so that the control valve switches to control the action of the corresponding actuator 20. After the corresponding actuator 20 moves into place, the oil pressure in its oil inlet chamber increases, triggering the reversal of the pilot valve. The pilot oil flows out through the pilot valve after the reversal and is used as the pilot oil of the working link to control the action of the next actuator 20.

[0061] As a preferred technical solution of this embodiment, in the initial state, the pilot valve can control the pilot oil to enter the pilot chamber of the corresponding control valve, while the pilot chamber of the control valve corresponding to the next actuator 20 returns oil. The control valve of the next actuator 20 remains in the neutral position, the corresponding actuator 20 is actuated, and the next actuator 20 is inactive. After the pilot valve is reversed, the pilot oil no longer enters the pilot chamber of the corresponding control valve, but instead enters the pilot chamber of the control valve corresponding to the next actuator 20 through the control of the pilot valve. The pilot chamber of the corresponding control valve returns oil. At this time, the corresponding control valve returns to the neutral position, and the high-pressure oil no longer impacts the corresponding actuator 20. The control valve corresponding to the next actuator 20 is reversed, controlling the pressure oil to enter the next actuator 20, and the next actuator 20 is actuated. In this way, the corresponding actuator 20 and the next actuator 20 are sequentially actuated. The number of working links and actuators 20 can be adjusted as needed, and they are sequentially connected according to the desired execution order, thereby achieving sequential actuation of multiple actuators 20.

[0062] As a preferred technical solution of this embodiment, each working link is provided with a control valve and a pilot valve. After the preceding pilot valve is switched, the pilot oil can flow through the preceding pilot valve to the oil inlet of the succeeding pilot valve, and circulate under the control of the succeeding pilot valve. Since all pilot valves initially maintain their initial state, when the pilot oil reaches the oil inlet of the succeeding pilot valve in the initial state, it can directly enter the pilot chamber of the control valve corresponding to the succeeding pilot valve through the succeeding pilot valve until the succeeding pilot valve switches and controls the pilot oil to flow to the oil inlet of the succeeding pilot valve. Preferably, the working link corresponding to the actuator 20 performing the final action may not be provided with a pilot valve, and the pilot oil is controlled by the preceding pilot valve to directly enter the pilot chamber of the control valve corresponding to the actuator 20 performing the final action by switching the preceding pilot valve.

[0063] As a preferred technical solution of this embodiment, the switching pressure of the pilot valve is slightly greater than the maximum load pressure of the corresponding actuator 20. Specifically, the oil inlet chamber of the actuator 20 is connected to the pilot pressure chamber of the corresponding pilot valve. When the pilot valve controls the pilot oil to enter the pilot chamber of the control valve, causing the control valve to switch direction, the control valve can control the inflow of oil into one chamber of the actuator 20 (this chamber is the oil inlet chamber) and the outflow of oil from the other chamber (this chamber is the oil outlet chamber). When the actuator 20 moves to the end of its stroke, the oil pressure in its oil inlet chamber increases, and this oil pressure triggers the pilot valve to switch direction. The oil inlet chamber of the actuator 20 is connected to the pilot pressure chamber of the corresponding working link pilot valve. The switching pressure of the pilot valve is set so that the control valve does not trigger the pilot valve to switch direction when controlling the actuator 20. Only when the actuator 20 moves to the end of its stroke and the oil pressure in its oil inlet chamber continues to rise will the pilot valve switch direction be triggered. To adjust the pilot valve's switching pressure, a pilot pressure chamber is formed at one end of the pilot valve spool. A spring and an adjusting screw are located at the other end. Turning the adjusting screw adjusts the spring's pre-compression, and thus the pilot valve's opening pressure. Preferably, the pilot valve's switching pressure is set 1-3 MPa higher than the maximum load pressure of the corresponding actuator 20. This configuration prevents load fluctuations from affecting the pilot valve's switching behavior while also ensuring the pilot valve's switching response time when the actuator 20 reaches the end of its travel.

[0064] As a preferred technical solution of this embodiment, a pilot chamber is formed at each end of the control valve, with the corresponding pilot valve controlling the oil flow in and out of one of the pilot chambers. If actuator 20 is a cylinder, the pilot valve controls the oil flow in and out of one pilot chamber to extend actuator 20; the pilot valve controls the oil flow in and out of the other pilot chamber to retract actuator 20.

[0065] As a preferred technical solution of this embodiment, each working link includes a valve body, in which both the control valve and the pilot valve are assembled. When the number of actuators 20 is adjusted, the working link can be adjusted accordingly. Preferably, the valve body can be configured to include an intermediate valve body, with end covers provided at both ends of the intermediate valve body. The control valve is located within the intermediate valve body, and the ends of the control valve spool extend into the end covers to form a pilot cavity, and the pilot valve is assembled on the end covers. The pilot valve is assembled on the end cover at one end. During assembly, the position of the end cover equipped with the pilot valve can be adjusted so that the pilot valve corresponds to the pilot cavity setting to control the actuator 20 to perform the desired action. The separate arrangement of the intermediate valve body and the end covers facilitates the adjustment of the position of the pilot valve.

[0066] As a preferred technical solution of this embodiment, the valve bodies of multiple working links can be stacked. The valve bodies of multiple working links can be stacked according to the action sequence of the actuator 20, or they do not need to be stacked according to the action sequence of the actuator 20. The pilot valves can be on the same side or different sides of the valve body. It is only necessary for the oil outlet of the pilot valve corresponding to the actuator 20 of the previous action to be connected to the oil inlet of the pilot valve corresponding to the actuator 20 of the next action through the external pipe 7. Preferably, in order to save external pipes 7, facilitate the arrangement of external pipes 7, and avoid the problem of entanglement and interference of external pipes 7, the valve bodies can be stacked according to the action sequence of the actuator 20, and all pilot valves are located on the same side of the valve body. Two adjacent pilot valves are connected through the external pipe 7 to facilitate the circulation of pilot oil.

[0067] As a preferred technical solution of this embodiment, the pilot valve includes an oil inlet, an oil return port, a working oil port, and an oil outlet. The oil inlet introduces pilot oil, the oil return port is connected to the oil tank 40, the working oil port is connected to the pilot chamber of the corresponding control valve, and the oil outlet is connected to the oil inlet of the pilot valve in the working link corresponding to the next actuator 20. In the initial state, the oil inlet and the working oil port are connected, and the oil outlet and the oil return port are connected. After reversing, the working oil port and the oil return port are connected, and the oil inlet and the oil outlet are connected. The oil outlet of the preceding pilot valve is connected to the oil inlet of the following pilot valve via an external pipe 7.

[0068] As a preferred technical solution of this embodiment, the control valve is a three-position valve. When the control valve is in the neutral position, pressurized oil does not enter the corresponding actuator 20. When the control valve is switched to the working position, pressurized oil can enter one chamber of the actuator 20 under the control of the control valve, and the other chamber of the actuator 20 returns oil. Preferably, the multi-way valve also forms a neutral unloading oil passage 6, through which all control valves are connected in series. When all control valves are in the neutral position, the neutral unloading oil passage 6 is connected, and the pressurized oil can flow directly through the neutral unloading oil passage 6 to relieve pressure.

[0069] In order to ensure the safety of the system, the multi-way valve further includes a safety link 5, which includes a safety valve 51. When the system pressure is too high, the pressure oil can be relieved through the safety valve 51. Preferably, the safety link 5 can be located upstream of all working links.

[0070] This embodiment also provides a hydraulic system comprising an oil source, the aforementioned multi-way valve, and an actuator 20. The oil source may include a pressure oil source 30 and a pilot oil source. The pressure oil source 30 is used to provide pressure oil, while the pilot oil source is used to provide pilot oil. The pressure oil source 30 is used to provide pressure oil to each control valve, while the pilot oil source provides pilot oil to the pilot valve corresponding to the actuator 20 performing the first action, and oil is fed in under the control of the pilot signal. There are at least two actuators 20, each connected to a corresponding working control valve.

[0071] like Figure 2 As shown, taking two working links and two actuators 20 as an example, the two working links are respectively the first working link 1 and the second working link 2, and the two actuators 20 are respectively the first actuator 201 and the second actuator 202. The first working link 1 is set for the first actuator 201, and the second working link 2 is set for the second actuator 202. The first actuator 201 performs the first action, and the second actuator 202 performs the subsequent action.

[0072] like Figure 3 As shown, the first working link 1 includes a first control valve 11 and a first pilot valve 12 . The first control valve 11 controls the flow of pressure oil into and out of the first actuator 201 , and the first pilot valve 12 controls the switching of the first control valve 11 .

[0073] like Figure 3-4 As shown, the first control valve 11 is a three-position valve. When the first control valve 11 is in the middle position, the pressure oil cannot enter the first actuator 201; when the first control valve 11 is in two working positions, the first control valve 11 controls the pressure oil to enter one cavity of the first actuator 201, and the other cavity of the first actuator 201 returns oil.

[0074] As a preferred technical solution of this embodiment, the first control valve 11 is a three-position, six-way valve. It includes ports P11, P12, T1, A1, B1, and C1. Pressurized oil is supplied to ports P11 and P12. Port T1 is connected to the oil tank 40. Ports A1 and B1 are connected to the two chambers of the first actuator 201, respectively. Port C1 is connected to the second control valve 21. When the first control valve 11 is in the neutral position, port P12 is connected to port C1, and the other ports are disconnected. Pressurized oil flows through the first control valve 11 to the second control valve 21. When the first control valve 11 is in the first operating position, port P11 is connected to port B1, and port A1 is connected to port T1. When the first control valve 11 is in the second operating position, port P11 is connected to port A1, and port B1 is connected to port T1.

[0075] As a preferred technical solution of this embodiment, the first control valve 11 changes direction under the action of the pilot pressure. A first pilot chamber 111 is formed at both ends of the first control valve 11. The first control valve 11 changes direction under the action of the pilot pressures a1 and b1 at both ends. Elastic parts are respectively provided in the two first pilot chambers 111. When no pilot pressure is introduced at both ends of the first control valve 11, the first control valve 11 is reset to the middle position under the action of the elastic parts at both ends.

[0076] like Figure 3 、 5As shown, the first pilot valve 12 is a two-position valve, which controls the pilot pressure at one end of the first control valve 11. In this embodiment, the first pilot valve 12 controls the input of the pilot pressure b1 of the first control valve 11. The first pilot valve 12 is a two-position valve. When the first pilot valve 12 is in the initial position, the pilot oil reaching the first working link 1 can enter the first pilot chamber 111 of the first control valve 11 through the first pilot valve 12, forming the pilot pressure b1, causing the first control valve 11 to switch direction. The first control valve 11 controls the pressure oil to enter one chamber of the first actuator 201, and the other chamber of the first actuator 201 returns oil, and the first actuator 201 performs the prior action; after the first pilot valve 12 is switched, the pilot oil reaching the first working link 1 flows to the second working link 2 through the first pilot valve 12 and is used as the pilot oil of the second working link 2.

[0077] As a preferred technical solution of this embodiment, the first pilot valve 12 is a two-position, four-way valve. The first pilot valve 12 includes an oil inlet p1, an oil return port t1, a working oil port m1, and an oil outlet n1. The oil inlet p1 introduces pilot oil, the oil return port t1 is connected to the oil tank 40, the working oil port m1 is connected to the first pilot chamber 111 of the first control valve 11, and the oil outlet n1 is connected to the second pilot chamber of the second control valve 21. In the initial state, the oil inlet p1 is connected to the working oil port m1, and the oil outlet n1 is connected to the oil return port t1. The pilot oil enters the first pilot chamber 111, causing the first control valve 11 to reverse direction. After the first pilot valve 12 reverses direction, the oil inlet p1 is connected to the oil outlet n1, and the working oil port m1 is connected to the oil return port t1. The pilot oil is supplied to the second pilot chamber of the second control valve 21, and the oil is returned to the first pilot chamber 111 of the first control valve 11.

[0078] As a preferred technical solution of this embodiment, the first pilot valve 12 is switched under the pressure of the oil inlet chamber of the first actuator 201. Figure 3 As shown, when the pilot oil generates pilot pressure b1, the pressure oil enters the rod chamber of the first actuator 201, which serves as the oil inlet chamber. The rodless chamber of the first actuator 201 returns oil, which serves as the oil return chamber. The first actuator 201 retracts, and the rod chamber of the first actuator 201 communicates with the pilot pressure chamber of the first pilot valve 12 via the first oil passage 13. After the rod chamber of the first actuator 201 retracts to its maximum extent due to the inflow of oil, pressure oil continues to enter the rod chamber of the first actuator 201, causing the pressure in the rod chamber to rise. When the pressure in the rod chamber reaches a certain value, the first pilot valve 12 is driven to reverse direction. Alternatively, after the first pilot valve 12 controls the switching of the first control valve 11 and oil is introduced into the rodless chamber of the first actuator 201 , the rodless chamber of the first actuator 201 is connected to the pilot pressure chamber of the first pilot valve 12 via the first oil passage 13 .

[0079] like Figure 6 As shown, in terms of specific structure, taking the structure of the first working unit 1 as an example, the first working unit 1 includes a first valve body 14, and the first control valve 11 and the first pilot valve 12 are both assembled in the first valve body 14. That is, the first working unit 1 can be used as a module.

[0080] As a preferred technical solution of this embodiment, the first valve body 14 can be configured as a split structure, comprising a first intermediate valve body 141, with first end caps 142 disposed at each end of the first intermediate valve body 141. The first control valve 11 is assembled within the first intermediate valve body 141, with both ends of the first control valve 11 extending into the first end cap 142 to form two first pilot chambers 111. The first pilot valve 12 is assembled within one of the first end caps 142, controlling the flow of pilot oil into and out of the adjacent first pilot chambers 111. The split structure facilitates adjustment of the corresponding operational relationship between the first pilot valve 12 and the first pilot chamber 111. Preferably, the oil inlet p1 of the first pilot valve 12 extends through an internal oil passage to the outer surface of the first end cap 142 of the first valve body 14, forming an oil port X to facilitate the introduction of pilot oil. The oil outlet n1 of the first pilot valve 12 extends through an internal oil passage to the outer surface of the first end cap 142 of the first valve body 14, forming an oil port Z to facilitate the flow of pilot oil to the next working section.

[0081] As a preferred technical solution of this embodiment, the first pilot valve 12 includes a first pilot valve spool 121. A first spring 122 is disposed at one end of the first pilot valve spool 121. A first adjusting screw 123 is also provided. The first adjusting screw 123 acts on the first spring 122 to adjust the pre-compression of the first spring 122, thereby adjusting the switching pressure of the first pilot valve 12. Preferably, the switching pressure of the first pilot valve 12 is slightly greater than the maximum load pressure of the first actuator 201. Preferably, the switching pressure of the first pilot valve 12 is set 1-3 MPa higher than the maximum load pressure of the first actuator 201.

[0082] like Figure 7 As shown, the second working link 2 includes a second control valve 21, which is used to control the operation of the second actuator 202. When there are only two actuators 20, the second pilot valve may not be provided. The oil outlet n1 of the first pilot valve 12 can be directly connected to the second pilot chamber of the second control valve 21.

[0083] like Figure 7-8 As shown, the second control valve 21 has a substantially identical structure to the first control valve 11. The second control valve 21 is a three-position valve. When in its neutral position, pressurized oil cannot enter the second actuator 202. When in its two working positions, the second control valve 21 controls pressurized oil to enter one chamber of the second actuator 202, while the other chamber of the second actuator 202 returns oil.

[0084] As the preferred technical solution of this embodiment, the second control valve 21 is a three-position six-way valve. The second control valve 21 includes oil port P21, oil port P22, oil port T2, oil port A2, oil port B2 and oil port C2. The pressure oil is supplied to the oil port P21, the oil port P22 is connected to the oil port C1, the oil port T2 is connected to the oil tank 40, the oil port A2 and the oil port B2 are respectively connected to the two chambers of the second actuator 202, and the oil port C2 can be connected to the oil tank 40. When the second control valve 21 is in the middle position, the oil port P22 is connected to the oil port C2, and the other oil ports are not connected. When the first control valve 11 and the second control valve 21 are both in the middle position, the pressure oil can flow to the oil tank 40 through the first control valve 11 and the second control valve 21; when the second control valve 21 is in the first working position, the oil port P21 is connected to the oil port B2, and the oil port A2 is connected to the oil port T2; when the second control valve 21 is in the second working position, the oil port P21 is connected to the oil port A2, and the oil port B2 is connected to the oil port T2.

[0085] Structurally, the second working unit 2 includes a second valve body, which has a structure essentially identical to that of the first valve body. The second valve body can be configured as a second intermediate valve body and two second end caps. A second control valve 21 is assembled within the second intermediate valve body, with both ends of the second control valve 21 extending into the second end caps to form a second pilot chamber. An oil port X is provided on the outer surface of the second valve body of the second working unit 2. This port X directly communicates with the second pilot chamber of the second control valve 21 for introducing pilot oil. The oil port Z of the first working unit 1 communicates with the oil port X of the second working unit 2 via an external pipeline 7.

[0086] During assembly, the first valve body 14 and the second valve body are stacked and fixed, and the oil port Z of the first working unit 1 is connected to the oil port X of the second working unit 2 via the external pipe 7. To facilitate assembly, the oil ports X and Z of the first working unit 1 can be arranged on the same first end cover 142. This first end cover 142 is located on the same side as the second end cover of the second working unit 2, which is provided with the oil port X, to facilitate the installation of the external pipe 7.

[0087] When the multi-way valve described above is used in a hydraulic system to control the sequential operation of two actuators 20, the pressure oil source 30 pumps out pressure oil, which is supplied to port P11 of the first control valve 11 and port P21 of the second control valve 21. Pressure oil is also supplied to port P12 of the first control valve 11. The pilot oil source provides pilot oil to the first pilot valve 12, specifically to port X of the first working link 1.

[0088] like Figure 2As shown, in the initial state, the pilot signal is not issued, the first control valve 11 and the second control valve 21 are both in the middle position, and the pressure oil pumped out by the pressure oil source 30 is directly unloaded into the oil tank 40 through the middle position unloading oil channel 6.

[0089] When the pilot signal is issued, the pilot oil enters the first pilot chamber 111 of the first control valve 11 through the first pilot valve 12, causing the first control valve 11 to switch direction. At this time, the pressure oil enters the rod chamber of the first actuator 201 through the first control valve 11, and the rodless chamber of the first actuator 201 returns oil, and the first actuator 201 performs a retraction action, such as Figure 9 shown.

[0090] After the first actuator 201 retracts to the end of its stroke, the inflow of pressurized oil increases the oil pressure in the rod chamber of the first actuator 201. When the reversing pressure of the first pilot valve 12 is reached, the first pilot valve 12 is triggered to reverse, and the pilot oil enters the second pilot chamber of the second control valve 21 through the first pilot valve 12, causing the second control valve 21 to reverse. The pressurized oil enters the rod chamber of the second actuator 202 through the second control valve 21, and the rodless chamber of the second actuator 202 returns oil, causing the second actuator 202 to retract. At the same time, the first pilot chamber 111 of the first control valve 11 is connected to the oil tank 40 through the first pilot valve 12, and the first control valve 11 returns to the neutral position. The pressurized oil will not impact the first actuator 201. Figure 10 shown.

[0091] The above describes the process of sequentially retracting the first and second actuators 201, 202 using the first and second working links 1, 2. By varying the corresponding control relationship between the first pilot valve 12 and the pilot chambers of the two control valves, the two actuators 20 can also be extended sequentially, with the first actuator 201 retracting while the second actuator 202 extends, or vice versa.

[0092] In addition to two working links controlling the sequential operation of two actuators 20, additional working links can be added to control the sequential operation of at least three actuators 20. Specifically, the structure of the working link that performs the final action can be the same as that of the second working link 2 described above, while the other working links can adopt the same structure as that of the first working link 1 described above. The working links are connected to the corresponding actuators 20, and adjacent working links can be connected to each other via external pipes 7.

[0093] Example 2

[0094] like Figure 11-13As shown, this embodiment is basically the same as the first embodiment, except that the working link corresponding to the actuator 20 that performs the final action is also provided with a pilot valve.

[0095] like Figure 11 As shown, taking two working links and two actuators 20 as an example, the structure of the first working link 1 is the same as that of the first embodiment, and the second working link 2 includes a second control valve 21 and a second pilot valve 22. The second pilot valve 22 controls the pilot oil in and out of the second pilot chamber of the second control valve 21.

[0096] like Figure 12 As shown, the second pilot valve 22 has a substantially identical structure to the first pilot valve 12. The second pilot valve 22 is a two-position valve that controls the pilot pressure at one end of the second control valve 21. In this embodiment, the second pilot valve 22 controls the input of the pilot pressure b2 to the second control valve 21. When the second pilot valve 22 is in its initial position, the pilot oil flowing out of the first pilot valve 12 can enter the second pilot chamber of the second control valve 21 through the second pilot valve 22, generating pilot pressure b2, causing the second control valve 21 to reverse direction. The second control valve 21 controls the pressure oil to enter one chamber of the second actuator 202, while the other chamber of the second actuator 202 returns oil, and the second actuator 202 performs the subsequent action. After the second pilot valve 22 reverses direction, the pilot oil reaching the second working link 2 flows out of the second working link 2 through the second pilot valve 22.

[0097] As a preferred technical solution of this embodiment, the second pilot valve 22 includes an oil inlet p2, an oil return port t2, a working oil port m2, and an oil outlet n2. The oil inlet p2 is connected to the oil outlet n1 of the first pilot valve 12, the oil return port t2 is connected to the oil tank 40, the working oil port m2 is connected to the second pilot chamber of the second control valve 21, and the oil outlet n2 can be connected to the oil tank 40. In the initial state, the oil inlet p2 is connected to the working oil port m2, and the oil outlet n2 is connected to the oil return port t2. The pilot oil flowing out of the first pilot valve 12 can enter the second pilot chamber through the second pilot valve 22, causing the second control valve 21 to switch direction. After the second pilot valve 22 switches direction, the oil inlet p2 is connected to the oil outlet n2, the working oil port m2 is connected to the oil return port t2, the pilot oil flows out of the second working valve 2, the second pilot chamber of the second control valve 21 returns to oil, and the second control valve 21 is reset to the neutral position.

[0098] As a preferred technical solution of this embodiment, the second pilot valve 22 switches under the pressure of the oil inlet chamber of the second actuator 202. Figure 11As shown, when the pilot oil generates pilot pressure b2, the pressure oil enters the rod chamber of the second actuator 202, which becomes the oil inlet chamber. The rodless chamber of the second actuator 202 returns oil, becoming the oil return chamber. The second actuator 202 retracts, and the rod chamber of the second actuator 202 communicates with the pilot pressure chamber of the second pilot valve 22 via the second oil passage 23. After the rod chamber of the second actuator 202 retracts to its maximum extent due to the inflow of oil, pressure oil continues to enter the rod chamber of the second actuator 202, causing the pressure in the rod chamber to rise. When the pressure in the rod chamber reaches a certain value, the second pilot valve 22 is driven to reverse direction. Alternatively, after the second pilot valve 22 controls the switching of the second control valve 21 and oil enters the rodless chamber of the second actuator 202 , the rodless chamber of the second actuator 202 is connected to the pilot pressure chamber of the second pilot valve 22 via the second oil passage 23 .

[0099] Specifically, the second pilot valve 22 is assembled within a second end cap. The second pilot valve 22 includes a second pilot valve spool. A second spring and a second adjusting screw are disposed at one end of the second pilot valve spool. The second adjusting screw is used to adjust the pre-compression of the second spring, thereby adjusting the switching pressure of the second pilot valve 22. Preferably, the switching pressure of the second pilot valve 22 is set 1-3 MPa higher than the maximum load pressure of the second actuator 202.

[0100] The number of work links is adjustable, such as Figure 13 As shown, four working links are provided: a first working link 1, a second working link 2, a third working link 3, and a fourth working link 4. The first working link 1 corresponds to the first actuator 201, the second working link 2 corresponds to the second actuator 202, the third working link 3 corresponds to the third actuator 203, and the fourth working link 4 corresponds to the fourth actuator 204. The first working link 1 includes a first control valve 11 and a first pilot valve 12, the second working link 2 includes a second control valve 21 and a second pilot valve 22, the third working link 3 includes a third control valve 31 and a third pilot valve 32, and the fourth working link 4 includes a fourth control valve 41 and a fourth pilot valve 42. The first pilot valve 12 and the second pilot valve 22, the second pilot valve 22 and the third pilot valve 32, and the third pilot valve 32 and the fourth pilot valve 42 are all connected by an external pipeline 7, facilitating the flow of pilot oil to the next working link under the control of the pilot valves.

[0101] Specifically, the first valve body 14 of the first working unit 1, the second valve body of the second working unit 2, the third valve body of the third working unit, and the fourth valve body of the fourth working unit are stacked and fixed. The oil port Z of the first working unit 1 is connected to the oil port X of the second working unit 2 via the external pipe 7; the oil port Z of the second working unit 2 is connected to the oil port X of the third working unit 3 via the external pipe 7; and the oil port Z of the third working unit 3 is connected to the oil port X of the fourth working unit 4 via the external pipe 7.

[0102] The pilot pressure chamber of the first pilot valve 12 is connected to the oil inlet chamber of the first actuator 201 (in this embodiment, the rod chamber of the first actuator 201 is the oil inlet chamber) through the first oil circuit 13; the pilot pressure chamber of the second pilot valve 22 is connected to the oil inlet chamber of the second actuator 202 (in this embodiment, the rod chamber of the second actuator 202 is the oil inlet chamber) through the second oil circuit 23; the pilot pressure chamber of the third pilot valve 32 is connected to the oil inlet chamber of the third actuator 203 (in this embodiment, the rod chamber of the third actuator 203 is the oil inlet chamber) through the third oil circuit 33; the pilot pressure chamber of the fourth pilot valve 42 is connected to the oil inlet chamber of the fourth actuator 204 (in this embodiment, the rod chamber of the fourth actuator 204 is the oil inlet chamber) through the fourth oil circuit 43.

[0103] like Figure 13 As shown, four actuators 20 perform the retraction action in sequence. In addition, the number of working links can be adjusted as required.

[0104] Example 3

[0105] like Figure 14 As shown, the structures of the four working links in this embodiment are basically the same as those in the second embodiment, except that the third pilot valve 32 of the third working link 3 controls the input of the pilot pressure a3 at the other end of the third control valve 31, and the third control valve 31 controls the third actuator 203 to perform an extension action; the rodless chamber of the third actuator 203 is an oil inlet chamber, and the rodless chamber of the third actuator 203 is connected to the pilot pressure chamber of the third pilot valve 32 through the third oil circuit 33.

[0106] like Figure 14 As shown, the four actuators 20 of this embodiment perform the retraction-retraction-extension-retraction action in sequence. In addition to the above-mentioned sequential action combination, other sequential action combinations can also be set.

[0107] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A multi-way valve for controlling the sequential action of at least two actuators (20), characterized in that: It comprises at least two working links, wherein the working links are arranged corresponding to the execution elements (20), and the working links include: A control valve, wherein the control valve controls the action of a corresponding actuator; The pilot valve is set for the control valve, and the pilot valve controls the pilot oil in and out of the control valve; in the initial state, the pilot oil can enter the control valve through the pilot valve, so that the control valve switches to control the action of the corresponding actuator; after the corresponding actuator moves into place, the oil pressure in its oil inlet chamber increases, triggering the pilot valve to switch direction, and the pilot oil flows out through the switched pilot valve and is used as the pilot oil of the working link to control the action of the next actuator.

2. A multi-way valve according to claim 1, characterized in that: After the pilot valve is switched, the pilot chamber of the corresponding control valve returns oil.

3. A multi-way valve according to claim 1, characterized in that: The switching pressure of the pilot valve is slightly greater than the maximum load pressure of the corresponding actuator.

4. A multi-way valve according to claim 1, characterized in that: Both ends of the control valve are formed with a pilot cavity, and the pilot valve controls the pilot oil to flow in and out of one of the pilot cavities.

5. A multi-way valve according to any one of claims 1 to 4, characterized in that: The pilot valve comprises an oil inlet, an oil return port, a working oil port and an oil outlet. The oil inlet introduces pilot oil, the oil return port is connected to an oil tank (40), the working oil port is connected to a pilot chamber of a corresponding control valve, and the oil outlet is connected to the oil inlet of a pilot valve of a working link corresponding to the next actuator. In an initial state, the oil inlet is connected to the working oil port, and the oil outlet is connected to the oil return port; after reversing, the working oil port is connected to the oil return port, and the oil inlet is connected to the oil outlet.

6. A multi-way valve according to claim 5, characterized in that: The working link comprises a valve body, in which the corresponding control valve and pilot valve are assembled.

7. A multi-way valve according to claim 6, characterized in that: The oil inlet and the oil outlet of the pilot valve both extend to the surface of the valve body, and the oil outlet of the pilot valve is connected to the oil inlet of the next pilot valve through an external pipeline (7).

8. The multi-way valve according to claim 6, characterized in that: The valve body includes an intermediate valve body, both ends of the intermediate valve body are provided with end covers, the control valve is installed in the intermediate valve body, both ends of the control valve extend into the end covers to form the pilot cavity, and the pilot valve is assembled on the end covers.

9. A multi-way valve according to any one of claims 5 to 8, characterized in that: All working links are stacked according to the action sequence of the actuators, and all pilot valves are located on the same side of the valve body (14).

10. The multi-way valve according to claim 1, characterized in that: The utility model also comprises a middle position unloading oil passage (6), wherein the middle position unloading oil passage (6) passes through all the control valves.

11. A hydraulic system for controlling sequential actions, characterized in that: include: Oil source, providing pressure oil and pilot oil; The multi-way valve according to any one of claims 1 to 10, wherein the pressure oil is supplied to each control valve, and the pilot oil is supplied to the pilot valve of the working link corresponding to the actuator performing the first action; There are at least two actuators (20), and the actuators (20) are connected to the control valves of the corresponding working links.

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