A multi-way valve and a hydraulic system for controlling sequential actions

Abstract

The present application relates to the technical field of hydraulic pressure, in particular to a multi-way valve and a hydraulic system for controlling sequential action. A multi-way valve for controlling sequential action of at least two execution elements, comprising at least two working links, the working links are arranged corresponding to the execution elements, the working links comprise: a control valve for controlling action of the corresponding execution element; a pilot valve arranged corresponding to the control valve, the pilot valve controls the pilot oil to flow into or out of the control valve; in the initial state, the pilot oil can flow into the control valve through the pilot valve, so that the control valve reverses to control the action of the corresponding execution element; after the corresponding execution element moves to the position, the oil pressure in the oil inlet cavity of the execution element rises to trigger the pilot valve to reverse, the pilot oil flows out through the reversed pilot valve, and is used as the pilot oil of the working link corresponding to the execution element for the next action. The technical problem of the prior art that the hydraulic system has many complicated hydraulic elements and oil paths, and the oil liquid through the sequence valve causes pressure loss is solved.

Description

Technical Field

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

[0002] In existing technologies, for hydraulic systems controlled by hydraulic multi-way valves, a pilot signal typically controls one valve core of the multi-way valve to switch to one side, thereby enabling oil to be output from the inlet of the multi-way valve to the corresponding working port.

[0003] like Figure 1 As shown, taking the two-way hydraulic control valve of the open-center system as an example, the hydraulic pump 1' outputs oil and connects to port P' of the multi-way valve. Pilot signals a1' and b1' control the switching of the first valve core 2', and pilot signals a2' and b2' control the switching of the second valve core 4'. After the pilot signal a1' causes the first valve core 2' to switch, the oil at port P' enters the small chamber of the first cylinder 3' through the first valve core 2', and the large chamber of the first cylinder 3' returns to port T' through the first valve core 2', returning to the oil tank. The rest of the control logic is the same. If it is necessary to achieve the action of extending the first cylinder 3' and then extending the second cylinder 5', a pilot signal a1' needs to be input. After the first cylinder 3' extends to the end of its stroke, the pilot pressure of a1' is unloaded. Then, a pilot signal a2' is input. After the second cylinder 5' extends to the end of its stroke, the pressure of a2' is unloaded, ending the movement. The above control process requires multiple control pilot signals, and these pilot signals must be given in sequence, making the operation cumbersome and difficult to control.

[0004] To achieve sequential operation of control actuators, existing technologies have developed schemes for controlling the sequence of actuator actions. For example, application number CN201911071335.1 discloses a hydraulic system, method, and engineering vehicle for achieving sequential operation of an engineering vehicle mechanism. This scheme uses a sequence valve between a directional valve and the actuator cylinder. The sequence valve is switched by the cylinder reaching the end of its stroke, thus controlling the sequential action of the actuators. When the three-position four-way solenoid directional valve switches to the left, oil first enters the small chamber of the locking cylinder. After reaching the end of its stroke, sequence valve II opens, allowing oil to enter the large chamber of the lifting cylinder, which then reaches its end of its stroke. When the three-position four-way solenoid directional valve switches to the right, oil first enters the small chamber of the lifting cylinder. After reaching the end of its stroke, sequence valve I opens, allowing oil to enter the large chamber of the locking cylinder. This scheme controls the sequential action of the two actuators through a solenoid directional valve and an external sequence valve.

[0005] For example, document CN201911400683.9 discloses a novel hydraulic system with a mechanism to prevent sequential action misalignment. This scheme uses the back pressure of the first-acting cylinder to close the sequence valve. After the first-acting cylinder reaches the end of its stroke, the back pressure becomes zero, and the spring force causes the sequence valve to switch, allowing the subsequent-acting cylinder to move. When the action begins in sequence 1 (first cylinder retracts, second cylinder extends), the right electromagnet of the Y-type functional three-position four-way solenoid directional valve is energized, connecting the P and B ports and the A and T ports of the valve. Pressure oil P flows through the bidirectional hydraulic lock and enters the rod chamber of the first cylinder. Simultaneously, oil in the rodless chamber flows through the pilot-operated sequence valve group and the bidirectional hydraulic lock, and then returns to the oil tank through the passage from the A port to the T port of the Y-type functional three-position four-way solenoid directional valve, thereby driving the piston rod to retract, causing the first cylinder to retract. At this point, back pressure is generated in the return oil chamber of the first cylinder, which drives the second logic valve to the open state, disconnecting the pilot oil circuit of the pilot-operated sequence valve group. The pilot-operated sequence valve group is in the closed state, and the second cylinder will not move. When the first cylinder retracts to its position, the oil in the return oil chamber of the first cylinder does not flow 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-operated sequence valve group. The pilot-operated sequence valve group opens, and the second cylinder begins to move. The process of moving in sequence 2 (second cylinder retracts, first cylinder extends) is also the same.

[0006] The two solutions described above can achieve sequential control of the actions of two actuators. However, both solutions require the addition of solenoid valves and multiple sequence valves, resulting in a larger number of hydraulic system components and more complex oil circuits. Adjusting the sequence of actions is cumbersome. In sequential actions, the output oil must pass through the sequence valve before being output to the cylinder, which causes pressure loss and reduces the efficiency of the hydraulic system. Summary of the Invention

[0007] To address the technical problem of numerous and complex hydraulic components and oil circuits in existing hydraulic systems, which can cause pressure loss when oil passes through sequence valves, this invention provides a multi-way valve and a hydraulic system for controlling sequential actions, thus solving the aforementioned technical problems.

[0008] To address the aforementioned technical problems, the present invention provides a multi-way valve for controlling the sequential operation of at least two actuators, comprising at least two working links, wherein each working link is configured corresponding to an actuator, and the working link includes:

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

[0010] A pilot valve is provided for the control valve. The pilot valve controls the entry and exit of pilot oil into the control valve. In the initial state, the pilot oil can enter the control valve through the pilot valve, causing the control valve to switch and control the corresponding actuator to move. After the corresponding actuator moves to the position, the oil pressure in its inlet chamber increases, triggering the pilot valve to switch. The pilot oil flows out through the switched pilot valve and is used as the pilot oil for the working link to control the movement of the next actuator.

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

[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, both ends of the control valve are formed with pilot chambers, and the pilot valve controls the pilot oil to enter and exit one of the pilot chambers.

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

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

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

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

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

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

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

[0021] The oil source provides pressurized oil and pilot oil;

[0022] A multi-way valve, wherein the pressurized oil is supplied to a control valve, and the pilot oil is supplied to the pilot valve of the working link corresponding to the actuator that performs the first action;

[0023] There are at least two actuators, and each actuator is connected to a control valve in its corresponding working link.

[0024] Based on the above technical solution, the technical effects that the present invention can achieve are as follows:

[0025] 1. The multi-way valve of the present invention has a working link set for each actuator. The pilot oil direction is controlled by a 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 switch and control the corresponding actuator to act first. When the corresponding actuator moves to the position, the oil pressure in the actuator inlet chamber begins to rise. The actuator inlet chamber is connected to the pilot pressure chamber of the pilot valve. The oil pressure in the inlet chamber triggers the pilot valve to switch. After the pilot valve switches, the pilot oil no longer enters the corresponding control valve, but flows out as the pilot oil for 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, controlling the pilot oil source to enter the corresponding control valve and controlling the corresponding actuator to act subsequently. This process continues in sequence to achieve the sequential action of all actuators. The multi-way valve of the present invention adds only 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 adding solenoid valves and multiple sequence valves in the prior art, 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 has high efficiency.

[0026] 2. In the multi-way valve of the present invention, after the pilot valve reverses, the pilot chamber of the corresponding control valve returns oil. After the pilot valve reverses, 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, which can protect 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 during the operation of the corresponding actuator, thus ensuring that the actuator moves to the correct position; the pilot valve will only be triggered to switch after the oil pressure in the oil inlet chamber continues to rise after the actuator has moved to the correct 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 two pilot valves and is in a low-pressure state, so that the next control valve is in the neutral position. After the pilot valve is reversed, the pilot oil can be controlled to flow out and be used as the pilot oil for the next control valve. The pilot chamber of the control valve in this link is connected to the return oil port and is in a low-pressure state. Taking the working links of two actuators operating sequentially as an example, in normal operation, initially, the pilot valves of both working links are in their initial state. Pilot oil arrives at the first working link first, enters the first control valve through the first pilot valve, causing the first control valve to switch to the working position. Pressure oil then enters the first actuator through the first control valve, causing the first actuator to operate first. When the first actuator reaches its position, oil continues to flow into its inlet chamber, increasing the oil pressure. This pressure triggers the first pilot valve to switch, and pilot oil flows through the switched first pilot valve to the second pilot valve. Simultaneously, the pilot chamber of the first control valve connects to the return port, depressurizing its pilot chamber. The first control valve returns to the neutral position, and the pressure oil will no longer impact the first actuator. The oil flowing to the second pilot valve will repeat the action of the first pilot valve, proceeding sequentially to achieve the sequential operation of at least two working links and control the sequential operation of at least two actuators.

[0029] 5. The multi-way valve of the present invention includes a valve body, a control valve and a pilot valve assembled in each working link, which facilitates the adjustment of the number of working links and their assembly; the oil inlet and outlet of the pilot valve extend to the surface of the valve body, which facilitates the connection between the pilot valves of the working links corresponding to the sequentially operating actuators. When the number of actuators increases, only the corresponding number of working links need to be added. The pilot valves of the working links corresponding to adjacent sequentially operating actuators can be connected through external pipes, which facilitates the increase or decrease of 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 two end caps. The pilot valve is mounted on one end cap, making it easy to adjust the pilot chamber controlled by the pilot valve. This allows for adjustment of the corresponding actuator's action. For example, when the pilot valve controls oil to enter one side of the pilot chamber of the control valve, the actuator extends; when the pilot valve controls oil to enter the other side of the pilot chamber of the control valve, the actuator retracts. That is, by adjusting the position of the end cap where the pilot valve is located, it acts on the corresponding pilot chamber, causing the actuator to perform the required action. This facilitates the realization of the required sequential actions 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. Since the external pipelines are located on the same side of the multi-way valve, 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 then the sequential action of at least two actuators is controlled. The whole process only needs to be controlled by one pilot signal, which is convenient for operation and control. Attached Figure Description

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

[0034] Figure 2 This is a hydraulic schematic diagram of the hydraulic system according to Embodiment 1 of the present invention;

[0035] Figure 3 The hydraulic schematic diagram for the first working link;

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

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

[0038] Figure 6 A schematic diagram of the structure of the first end cap on the first working link, on which the first pilot valve is installed;

[0039] Figure 7 The hydraulic schematic diagram for the second working link;

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

[0041] Figure 9 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 switch the first control valve.

[0042] Figure 10 The first pilot valve of the first working link reverses under the oil pressure of the oil inlet chamber of the first actuator, and delivers pilot oil 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 schematic diagram of the hydraulic system according to Embodiment 2 of the present invention;

[0044] Figure 12 for Figure 11 Enlarged view of part D;

[0045] Figure 13A hydraulic schematic diagram of a hydraulic system including four working links;

[0046] Figure 14 This is a hydraulic schematic diagram of the hydraulic system according to Embodiment 3 of the present invention;

[0047] In the diagram: 10-Multi-way valve; 1-First working link; 11-First control valve; 111-First pilot chamber; 12-First pilot valve; 121-First pilot valve core; 122-First spring; 123-First adjusting screw; 13-First oil passage; 14-First valve body; 141-First intermediate valve body; 142-First end cap; 2-Second working link; 21-Second control valve; 22-Second pilot valve; 23-Second oil passage; 3-Third working link; 31-Third control valve; 32-Third pilot valve; 33-Third oil passage; 4-Fourth working link; 41-Fourth control valve; 42-Fourth pilot valve; 43-Fourth oil passage; 5-Safety link; 51-Safety valve; 6-Neutral unloading oil passage; 7-External pipeline;

[0048] 20 - Actuating element; 201 - First actuating element; 202 - Second actuating element; 203 - Third actuating element; 204 - Fourth actuating element;

[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 Implementation

[0052] 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 following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" 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, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0055] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

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

[0057] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0058] Example 1

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

[0060] The working link includes a control valve and a pilot valve. The control valve controls the corresponding actuator 20 to move. The pilot valve is designed for the control valve and controls the flow of 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, causing the control valve to switch and control the corresponding actuator 20 to move. After the corresponding actuator 20 moves to its position, the oil pressure in its inlet chamber increases, triggering the pilot valve to switch. The pilot oil flows out through the switched pilot valve and is used as the pilot oil for the working link to control the next actuator 20 to move.

[0061] As a preferred technical solution in this embodiment, in the initial state, the pilot valve controls 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 operates, and the next actuator 20 does not operate. After the pilot valve reverses, 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 pilot valve control, 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 will no longer impact the corresponding actuator 20; the control valve corresponding to the next actuator 20 reverses, controlling the pressure oil to enter the next actuator 20, and the next actuator 20 operates. In this way, the sequential operation of the corresponding actuator 20 and the next actuator 20 is realized. The number of working links and actuators 20 can be adjusted as needed, and they can be sequentially connected according to the required execution order, thereby realizing the sequential operation of multiple actuators 20.

[0062] As a preferred embodiment, each working link is equipped with a control valve and a pilot valve. After the preceding pilot valve reverses, pilot oil can flow through the preceding pilot valve to the inlet of the following pilot valve. Under the control of the following pilot valve, it flows. Since all pilot valves initially remain in their initial state, when the pilot oil reaches the inlet of the following pilot valve in its initial state, it can directly enter the pilot chamber of the control valve corresponding to the following pilot valve, until the following pilot valve reverses and controls the pilot oil to flow to the inlet of the following pilot valve. Preferably, the working link corresponding to the actuator 20 that performs the final action may not be equipped with a pilot valve, and the pilot oil can directly enter the pilot chamber of the control valve corresponding to the actuator 20 that performs the final action by reversing the preceding pilot valve.

[0063] As a preferred technical solution in 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, the control valve can control one chamber of the actuator 20 to receive oil (this chamber is the oil inlet chamber); the other chamber to discharge oil (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 the oil pressure in the oil inlet chamber triggers the pilot valve to switch. The oil inlet chamber of the actuator 20 is connected to the pilot pressure chamber of the corresponding pilot valve in the working connection. The switching pressure of the pilot valve is set so that the control valve will not trigger the pilot valve to switch when controlling the actuator 20 to move. Only when the actuator 20 moves to the end of its stroke and the oil pressure in its oil inlet chamber continues to increase will the pilot valve to switch be triggered. To adjust the switching pressure of the pilot valve, a pilot pressure chamber is formed at one end of the pilot valve core, and a spring and an adjusting screw are provided at the other end of the pilot valve core. By rotating the adjusting screw, the pre-compression of the spring can be adjusted, thereby adjusting the opening pressure of the pilot valve. Preferably, the switching pressure of the pilot valve is set 1-3 MPa higher than the maximum load pressure of the corresponding actuator 20. This setting avoids load fluctuations affecting the switching of the pilot valve and also takes into account the response time of the pilot valve switching when the actuator 20 reaches the end of its stroke.

[0064] As a preferred embodiment, both ends of the control valve have pilot chambers, and the pilot valve controls the inlet and outlet of oil in one of the pilot chambers. When the actuator 20 is a hydraulic cylinder, the pilot valve controls the inlet and outlet of oil in one pilot chamber, which can perform an extension action corresponding to the actuator 20; the pilot valve controls the inlet and outlet of oil in the other pilot chamber, which can perform a retraction action corresponding to the actuator 20.

[0065] As a preferred embodiment, each working link includes a valve body, in which both a control valve and a pilot valve are assembled. When the number of actuators 20 is adjusted, the working link can be adjusted accordingly. Preferably, the valve body may include an intermediate valve body with end caps at both ends. The control valve is located within the intermediate valve body, and the two ends of the control valve core extend into the end caps to form pilot chambers. The pilot valve is assembled on the end caps. The pilot valve is assembled on one end cap. During assembly, the position of the end cap with the pilot valve can be adjusted so that the pilot valve corresponds to the pilot chamber, thereby controlling the actuator 20 to perform the required action. The separate arrangement of the intermediate valve body and the end caps facilitates the adjustment of the pilot valve position.

[0066] As a preferred technical solution in 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 operating sequence of the actuator 20, or they can be stacked without following the operating sequence of the actuator 20. The pilot valves can be located on the same side or different sides of the valve body; it is sufficient that the oil outlet of the pilot valve corresponding to the previously operating actuator 20 is connected to the oil inlet of the pilot valve corresponding to the next operating actuator 20 through an external pipe 7. Preferably, to save on the external pipe 7, facilitate the arrangement of the external pipe 7, and avoid the problems of tangling and interference of the external pipe 7, they can be stacked according to the operating sequence of the actuator 20, with all pilot valves located on the same side of the valve body, and adjacent pilot valves connected through an external pipe 7 to facilitate the flow of pilot oil.

[0067] As a preferred embodiment, the pilot valve includes an inlet, a return port, a working port, and an outlet. The inlet introduces pilot oil, the return port connects to the oil tank 40, the working port connects to the pilot chamber of the corresponding control valve, and the outlet connects to the inlet of the pilot valve in the working sequence corresponding to the next actuator 20. Initially, the inlet and working port are connected, and the outlet and return port are connected; after reversal, the working port and return port are connected, and the inlet and outlet are connected. The outlet of the previous pilot valve is connected to the inlet of the next pilot valve via an external pipe 7.

[0068] As a preferred embodiment, the control valve is a three-position valve. When the control valve is in the neutral position, the pressurized oil will not enter the corresponding actuator 20. When the control valve switches to the working position, the 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. All control valves are connected in series through the neutral unloading oil passage 6. When all control valves are in the neutral position, the neutral unloading oil passage 6 is in a connected state, and the pressurized oil can flow out directly through the neutral unloading oil passage 6 to relieve pressure.

[0069] To ensure system safety, the multi-way valve also includes a safety link 5, which includes a safety valve 51. When the system pressure is too high, the pressurized 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, including an oil source, the aforementioned multi-way valve, and actuators 20. The oil source may include a pressure oil source 30 and a pilot oil source. The pressure oil source 30 provides pressure oil, and the pilot oil source provides pilot oil. The pressure oil source 30 provides pressure oil to each control valve, and the pilot oil source provides pilot oil to the pilot valve corresponding to the actuator 20 that performs the initial action, and enters the system under the control of a pilot signal. There are at least two actuators 20, each connected to a control valve in its corresponding working sequence.

[0071] like Figure 2 As shown, taking two working links and two actuators 20 as an example, the two working links are the first working link 1 and the second working link 2, and the two actuators 20 are 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 action first, and the second actuator 202 performs the action later.

[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 pressure oil to enter and exit the first actuator 201, and the first pilot valve 12 controls the first control valve 11 to switch.

[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 neutral position, the pressure oil cannot enter the first actuator 201. When the first control valve 11 is in both working positions, 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.

[0074] As a preferred embodiment, the first control valve 11 is a three-position six-way valve. The first control valve 11 includes ports P11, P12, T1, A1, B1, and C1. Pressure oil is supplied to ports P11 and P12. Port T1 is connected to the oil tank 40. Ports A1 and B1 are respectively connected to the two chambers of the first actuator 201. 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 not connected. Pressure oil flows through the first control valve 11 to the second control valve 21. When the first control valve 11 is in the first working 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 working 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 switches under the action of pilot pressure. Both ends of the first control valve 11 have a first pilot chamber 111. The first control valve 11 switches under the action of pilot pressures a1 and b1 at both ends. Each of the two first pilot chambers 111 is provided with an elastic element. When no pilot pressure is introduced at either end of the first control valve 11, the first control valve 11 is reset to the neutral position under the action of the elastic elements at both ends.

[0076] like Figure 3 , 5As shown, the first pilot valve 12 is a two-position valve. The first pilot valve 12 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. 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. The first actuator 201 performs the prior action. After the first pilot valve 12 switches, the pilot oil reaching the first working link 1 flows through the first pilot valve 12 to the second working link 2, and is used as the pilot oil for the second working link 2.

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

[0078] As a preferred technical solution in this embodiment, the first pilot valve 12 switches under the pressure of the oil inlet chamber of the first actuator 201. For example... Figure 3 As shown, when the pilot oil forms a pilot pressure b1, the pressurized oil enters the rod chamber of the first actuator 201. The rod chamber of the first actuator 201 is the oil inlet chamber, and the rodless chamber of the first actuator 201 is the oil return chamber. The rodless chamber of the first actuator 201 is the oil return chamber. The first actuator 201 performs a retraction action. The rod chamber of the first actuator 201 is connected to the pilot pressure chamber of the first pilot valve 12 through the first oil passage 13. After the first actuator 201 retracts to its maximum extent due to the oil entering the rod chamber, the pressurized oil still enters the rod chamber of the first actuator 201, causing the pressure in the rod chamber to rise. When the pressure in the rod chamber rises to a certain value, it can push the first pilot valve 12 to switch. Alternatively, when the first pilot valve 12 controls the first control valve 11 to switch and allows oil to enter the rodless chamber of the first actuator 201, the rodless chamber of the first actuator 201 is configured to be 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 link 1 as an example, the first working link 1 includes a first valve body 14, and the first control valve 11 and the first pilot valve 12 are both assembled inside the first valve body 14. That is, the first working link 1 can be used as a module.

[0080] As a preferred embodiment, the first valve body 14 can be configured as a split structure, including a first intermediate valve body 141. First end caps 142 are respectively provided at both ends of the first intermediate valve body 141. A first control valve 11 is assembled inside the first intermediate valve body 141, with both ends of the first control valve 11 extending into the first end caps 142 to form two first pilot chambers 111. A first pilot valve 12 is assembled inside one of the first end caps 142, controlling the entry and exit of pilot oil in adjacent first pilot chambers 111. The split structure facilitates adjustment of the corresponding action 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, facilitating 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, facilitating the flow of pilot oil to the next working connection.

[0081] As a preferred embodiment, the first pilot valve 12 includes a first pilot valve core 121, one end of which is provided with a first spring 122, and a first adjusting screw 123 is also provided. The first adjusting screw 123 can act 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 to be 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, and the oil outlet n1 of the first pilot valve 12 may 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 and the first control valve 11 have basically the same structure. The second control valve 21 is a three-position valve. When the second control valve 21 is in the neutral position, the pressure oil cannot enter the second actuator 202. When the second control valve 21 is in both working positions, the second control valve 21 controls the pressure oil to enter one chamber of the second actuator 202, and the other chamber of the second actuator 202 returns oil.

[0084] As a preferred technical solution in 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. Pressure oil is supplied to oil port P21, oil port P22 is connected to oil port C1, oil port T2 is connected to oil tank 40, oil port A2 and oil port B2 are respectively connected to two chambers of the second actuator 202, and oil port C2 can be connected to oil tank 40. When the second control valve 21 is in the neutral position, oil port P22 is connected to oil port C2, and other oil ports are not connected to each other. When both the first control valve 11 and the second control valve 21 are in the neutral position, the pressurized 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, oil port P21 is connected to oil port B2, and oil port A2 is connected to oil port T2. When the second control valve 21 is in the second working position, oil port P21 is connected to oil port A2, and oil port B2 is connected to oil port T2.

[0085] Structurally, the second working link 2 includes a second valve body, the structure of which is basically the same as that of the first valve body. The second valve body can be configured to include a second intermediate valve body and two second end caps. The second control valve 21 is assembled in the second intermediate valve body, and both ends of the second control valve 21 extend into the second end caps to form a second pilot chamber. The outer surface of the second valve body of the second working link 2 is provided with an oil port X, which is directly connected to the second pilot chamber of the second control valve 21 for introducing pilot oil. The oil port Z of the first working link 1 is connected to the oil port X of the second working link 2 through an external pipe 7.

[0086] During assembly, the first valve body 14 and the second valve body are stacked and fixed together. The oil port Z of the first working link 1 and the oil port X of the second working link 2 are connected through the external pipe 7. To facilitate assembly, the oil ports X and Z of the first working link 1 can be set on the same first end cap 142. This first end cap 142 and the second end cap of the second working link 2 with the oil port X are located on the same side, which facilitates the installation of the external pipe 7.

[0087] When the aforementioned multi-way valve 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. A 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, no pilot signal is issued, and both the first control valve 11 and the second control valve 21 are in the neutral position. The pressure oil pumped out by the pressure oil source 30 is directly unloaded into the oil tank 40 through the neutral unloading oil passage 6.

[0089] When a pilot signal is issued, 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. At this time, pressure oil enters the rod chamber of the first actuator 201 through the first control valve 11, and oil returns from the rodless chamber of the first actuator 201. The first actuator 201 then performs a retraction action. Figure 9 As shown.

[0090] After the first actuator 201 retracts to the end of its stroke, the entry of pressurized oil increases the oil pressure in the rod chamber of the first actuator 201. When the pressure reaches the switching pressure of the first pilot valve 12, it triggers the switching of the first pilot valve 12. 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 switch. Pressurized oil enters the rod chamber of the second actuator 202 through the second control valve 21, and oil returns from the rodless chamber of the second actuator 202, causing the second actuator 202 to retract. Simultaneously, the first pilot chamber 111 of the first control valve 11 is connected to the oil tank 40 through the first pilot valve 12. The first control valve 11 returns to the neutral position, and the pressurized oil will not impact the first actuator 201. Figure 10 As shown.

[0091] The above describes the process of using the first working link 1 and the second working link 2 to control the first actuator 201 and the second actuator 202 to sequentially perform retraction actions. By changing the corresponding control relationship between the first pilot valve 12 and the pilot chambers of the two control valves, it is also possible to achieve the following: the two actuators 20 sequentially perform extension actions; or, the first actuator 201 performs a retraction action and the second actuator 202 performs an extension action; or, the first actuator 201 performs an extension action and the second actuator 202 performs a retraction action.

[0092] In addition to the two working links controlling the sequential operation of the two actuators 20, the sequential operation of at least three actuators 20 can be controlled by adding more working links. Specifically, the structure of the working link that performs the last action can be the same as the structure of the second working link 2 mentioned above, while the other working links adopt the same structure as the first working link 1 mentioned above. The working links are connected to the corresponding actuators 20, and adjacent working links can be connected to each other through external pipes 7.

[0093] Example 2

[0094] like Figure 11-13As shown, this embodiment is basically the same as embodiment one, except that the working link corresponding to the actuator 20 that performs the final action is also equipped 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 Embodiment 1. 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 to enter and exit the second pilot chamber of the second control valve 21.

[0096] like Figure 12 As shown, the second pilot valve 22 has a structure that is basically the same as that of the first pilot valve 12. The second pilot valve 22 is a two-position valve. The second pilot valve 22 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 of the second control valve 21. When the second pilot valve 22 is in the 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, forming the pilot pressure b2, which causes the second control valve 21 to switch. The second control valve 21 controls the pressure oil to enter one chamber of the second actuator 202, and the other chamber of the second actuator 202 returns oil. The second actuator 202 performs the subsequent action. When the second pilot valve 22 switches, the pilot oil that reaches the second working link 2 flows out of the second working link 2 through the second pilot valve 22.

[0097] As a preferred embodiment, the second pilot valve 22 includes an inlet p2, a return port t2, a working port m2, and an outlet n2. The inlet p2 is connected to the outlet n1 of the first pilot valve 12, the return port t2 is connected to the oil tank 40, the working port m2 is connected to the second pilot chamber of the second control valve 21, and the outlet n2 is connected to the oil tank 40. In the initial state, the inlet p2 is connected to the working port m2, and the outlet n2 is connected to the 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. After the second pilot valve 22 switches, the inlet p2 is connected to the outlet n2, the working port m2 is connected to the return port t2, the pilot oil flows out of the second working connection 2, the second pilot chamber of the second control valve 21 returns oil, and the second control valve 21 resets to the neutral position.

[0098] As a preferred technical solution in this embodiment, the second pilot valve 22 switches under the pressure of the oil inlet chamber of the second actuator 202. For example... Figure 11As shown, when the pilot oil forms a pilot pressure b2, the pressurized oil enters the rod chamber of the second actuator 202. The rod chamber of the second actuator 202 is the inlet chamber, and the rodless chamber of the second actuator 202 is the return chamber. The rodless chamber of the second actuator 202 is the return chamber. The second actuator 202 performs a retraction action. The rod chamber of the second actuator 202 is connected to the pilot pressure chamber of the second pilot valve 22 through the second oil passage 23. After the second actuator 202 retracts to its maximum extent, the pressurized oil still enters the rod chamber of the second actuator 202, causing the pressure in the rod chamber to rise. When the pressure in the rod chamber rises to a certain value, it can push the second pilot valve 22 to switch. Alternatively, when the rodless chamber of the second actuator 202 is filled with oil after the second pilot valve 22 controls the second control valve 21 to switch, 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] In terms of specific structure, the second pilot valve 22 is assembled inside a second end cap. The second pilot valve 22 may include a second pilot valve core, one end of which is provided with a second spring and a second adjusting screw. 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 to be 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, there are four working links: the first working link 1, the second working link 2, the third working link 3, and the 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 external pipes 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 link 1, the second valve body of the second working link 2, the third valve body of the third working link, and the fourth valve body of the fourth working link are stacked and fixed. The oil port Z of the first working link 1 is connected to the oil port X of the second working link 2 through an external pipe 7; the oil port Z of the second working link 2 is connected to the oil port X of the third working link 3 through an external pipe 7; and the oil port Z of the third working link 3 is connected to the oil port X of the fourth working link 4 through an 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 passage 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 passage 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 passage 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 passage 43.

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

[0104] Example 3

[0105] like Figure 14 As shown, the structure of the four working links in this embodiment is basically the same as that in Embodiment 2. The difference is 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 the extension action; the rodless chamber of the third actuator 203 is the 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 passage 33.

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

[0107] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit 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 includes at least two working links, each working link being configured corresponding to an actuator (20), each working link comprising: A control valve that controls the action of a corresponding actuator; A pilot valve is provided for the control valve. The pilot valve controls the entry and exit of pilot oil into and out of the control valve. The pilot valve includes an inlet, a return port, a working port, and an outlet. The inlet introduces pilot oil, the return port is connected to the oil tank (40), the working port is connected to the pilot chamber of the corresponding control valve, and the outlet is connected to the inlet of the pilot valve of the working link corresponding to the next actuator. In the initial state, the inlet and the working port are connected, and the outlet and the return port are connected. After reversal, the working port and the return port are connected, and the inlet and the outlet are connected. Initially, pilot oil enters the pilot chamber of the corresponding control valve through the pilot valve, causing the corresponding control valve to switch and control the corresponding actuator to act first. When the corresponding actuator moves to its position, the oil pressure in the actuator's inlet chamber begins to rise, connecting the actuator's inlet chamber with the pilot pressure chamber of the pilot valve. The oil pressure in the inlet chamber triggers the pilot valve to switch. After the pilot valve switches, the pilot oil no longer enters the corresponding control valve, but flows out as pilot oil for the working link of the actuator that will perform the next action. The pilot valve of the working link of the actuator that will perform the next action repeats the working process of the previous pilot valve, controlling the pilot oil source to enter the corresponding control valve and controlling the corresponding actuator to act subsequently. This process continues in sequence, achieving the sequential action of all actuators.

2. A multi-way valve according to claim 1, characterized in that, After the pilot valve reverses, 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 have pilot chambers, and the pilot valve controls the pilot oil to enter and exit one of the pilot chambers.

5. A multi-way valve according to claim 1, characterized in that, The working link includes a valve body, and a corresponding control valve and pilot valve are assembled in the valve body.

6. A multi-way valve according to claim 5, characterized in that, The inlet and outlet of the pilot valve both extend to the surface of the valve body, and the outlet of the pilot valve is connected to the inlet of the next pilot valve through an external pipe (7).

7. A multi-way valve according to claim 5, characterized in that, The valve body includes an intermediate valve body, with end caps at both ends of the intermediate valve body. The control valve is installed in the intermediate valve body, with both ends of the control valve extending into the end caps to form the pilot chamber. The pilot valve is assembled on the end caps.

8. A multi-way valve according to any one of claims 5-7, characterized in that, All working links are stacked in the order of the actuator's action, and all pilot valves are located on the same side of the valve body (14).

9. A multi-way valve according to claim 1, characterized in that, It also includes a mid-position unloading oil passage (6), which passes through all control valves.

10. A hydraulic system for controlling sequential actions, characterized in that, include: The oil source provides pressurized oil and pilot oil; The multi-way valve according to any one of claims 1-9, 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; At least two actuators (20) are connected to the control valve of the corresponding working link.

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