A large flow unloading valve structure based on pilot adaptive control

Abstract

The present invention relates to the technical field of unloading valves, and more specifically to a high-flow unloading valve structure based on pilot adaptive control, comprising a main valve body, wherein two main valve seats are provided at the top of the interior of the main valve body, and a main valve spool is provided on each of the two main valve seats; two one-way valve guide sleeves are provided at the bottom of the interior of the main valve body, and a one-way valve spool is provided on each of the two one-way valve guide sleeves, and the one-way valve spool is provided below the main valve spool; a mechanical pilot valve is provided at one end of the main valve body; and an electromagnetic pilot valve is provided at the top of one side of the mechanical pilot valve. Compared with the prior art, the present application ensures long-term stable operation of the system, prevents overload, reduces energy consumption, and extends equipment life by providing four hydraulic circuits that work together, thereby improving the system's response speed, stability, and control accuracy, and effectively enhancing the efficiency and reliability of the hydraulic system.

Description

Technical Field

[0001] The present invention relates to the technical field of unloading valves, and in particular to a large-flow unloading valve structure based on pilot adaptive control. Background Art

[0002] As one of the key hydraulic components in the hydraulic system of the pump station, the unloading valve's main function is to quickly unload the load of the hydraulic pump when the system pressure reaches the set value, prevent the system from overloading and ensure the safe operation of the equipment. The stability of this component is not only related to the normal operation of the hydraulic system, but also directly affects the overall pressure control, energy consumption management and response speed of the actuator of the pump station. If the unloading valve has hysteresis, leakage or excessive pressure fluctuations during operation, it may cause abnormal system pressure, thereby affecting the service life of the hydraulic pump, pipeline and actuator, and even causing equipment failure. Therefore, the performance stability of the unloading valve is very important. It needs to have precise pressure control capabilities, fast response characteristics and good sealing to ensure that the hydraulic system of the pump station can operate efficiently and reliably under various working conditions.

[0003] In the prior art, a Chinese patent document with the announcement number CN114877106A proposes to use a ball as a sealing member in an unloading valve, and the sealing form is changed to a line seal, which has a better sealing effect and is easier to process; using a ball as a sealing member, the force-bearing area of ​​the spherical convex surface is larger than the force-bearing area of ​​the original flat valve core, effectively reducing the impact loss of the high-pressure liquid medium; using a ball as a sealing member, it has an automatic guiding and positioning function, can automatically adjust and reset, and ensure reliable sealing, but consistent with the traditional method, in the traditional unloading valve, the valve usually lacks a special liquid path to automatically maintain the pressure balance of the pilot valve core, and the pressure fluctuation The movement of the valve core may easily lead to malfunction or response delay, thereby affecting the control accuracy and stability of the system, reducing the response speed of the hydraulic actuator, and there is no special reflux liquid circuit to guide the reflux of high-pressure liquid. When the pressure reaches the preset threshold, the liquid reflux cannot be quickly guided, resulting in prolonged system overload time, increasing the risk of equipment damage and wasting energy. In addition, the unloading valve only uses ball sealing and spring reset, and there is no special pressure balance control channel. When the hydraulic pressure fluctuates greatly, the valve core may be opened or closed untimely. Therefore, the present application discloses a large-flow unloading valve structure based on pilot adaptive control. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose a large flow unloading valve structure based on pilot adaptive control to solve the problem of lack of a dedicated fluid circuit to automatically maintain the pressure balance of the pilot valve core.

[0005] Based on the above objectives, the present invention provides a large-flow unloading valve structure based on pilot adaptive control, comprising a main valve body, wherein two main valve seats are provided at the top of the interior of the main valve body, and a main valve spool is provided on each of the two main valve seats; two one-way valve guide sleeves are provided at the bottom of the interior of the main valve body, and a one-way valve spool is provided on each of the two one-way valve guide sleeves, and the one-way valve spool is provided below the main valve spool;

[0006] a mechanical pilot valve, the mechanical pilot valve being disposed at one end of the main valve body and communicating with the main valve spool via a fluid passage to control the opening and closing of the main valve spool when the hydraulic system pressure rises, the mechanical pilot valve having a pilot spool disposed therein;

[0007] an electromagnetic pilot valve, the electromagnetic pilot valve being arranged at the top of one side of the mechanical pilot valve and being in communication with the main valve core through a fluid channel so as to adjust the state of the main valve core under the control of an external electrical signal;

[0008] A pilot filter is provided at the bottom of one side of the mechanical pilot valve. The pilot filter is used to filter the high-pressure liquid entering the electromagnetic pilot valve or the mechanical pilot valve to ensure stable operation of the system.

[0009] Preferably, two main valve springs are provided at the inner top end of the main valve body, and the bottom ends of the two main valve springs are fixedly connected to one side of the main valve core respectively. Two one-way valve springs are provided in the middle part of the main valve body, and the other ends of the two one-way valve springs are respectively embedded and installed on one side of the two one-way valve cores. Two main valve sleeves that are compatible with the main valve cores are provided on the top surface of the main valve body.

[0010] Preferably, a high-pressure liquid supply channel, a pump discharge channel, and an unloading return liquid channel are further provided on one side of the main valve body. The high-pressure liquid supply channel is located at the bottom of the main valve body and is arranged above the one-way valve guide sleeve 13. A high-pressure liquid supply port is provided on one side of the high-pressure liquid supply channel. The unloading return liquid channel is located at the top of the main valve body. The unloading return liquid channel is connected with the two main valve cores. An unloading return liquid port is provided on one side of the unloading return liquid channel. The pump discharge channel is arranged between the high-pressure liquid supply channel and the unloading return liquid channel. A pump discharge port is provided on one side of the pump discharge channel.

[0011] Preferably, the pilot valve core includes a pilot valve plug arranged on one side of the mechanical pilot valve, a push rod guide sleeve is provided on one side of the pilot valve plug, a push rod is slidably installed inside the push rod guide sleeve, a pilot valve seat is provided on one side of the push rod guide sleeve, a first ceramic ball guide sleeve is provided on one side of the pilot valve seat, a ceramic ball is provided inside the first ceramic ball guide sleeve, a spring guide rod is provided on the other side of the mechanical pilot valve, a second ceramic ball guide sleeve is also provided on the upper and lower sides of the spring guide rod, and a third ceramic ball guide sleeve is also provided on the inner side of the two second ceramic ball guide sleeves, an adjusting screw sleeve is provided on the side of the main valve body away from the pilot valve plug, a set screw is threadedly installed on the internal thread of the adjusting screw sleeve, one side of the set screw is against the spring guide rod, and an adjusting screw is also provided on one side of the mechanical pilot valve, one side of the set screw is fixedly connected to the adjusting screw, and one side of the adjusting screw is set to a hexagonal socket.

[0012] Preferably, the sealing method of the first ceramic ball guide sleeve and the ceramic ball is set to be line sealing.

[0013] Preferably, a first high-pressure pipe is provided on one side of the high-pressure liquid supply channel, the other end of the first high-pressure pipe is connected to the pilot valve core inside the mechanical pilot valve, and the first high-pressure pipe is provided at the rear of the push rod.

[0014] Preferably, a second high-pressure pipe is provided on one side of the pump discharge channel. The second high-pressure pipe passes through the pilot filter and then flows back into the pilot valve core and is connected to the main valve core. The second high-pressure pipe is first connected to the main valve core through the main valve sleeve.

[0015] Preferably, a third high-pressure pipe is provided on one side of the unloading return liquid channel, and the other end of the third high-pressure pipe is connected to the rear of the pilot valve core. The diameters of the first high-pressure pipe, the second high-pressure pipe, and the third high-pressure pipe are all set to 3 mm.

[0016] Preferably, a mechanical / electromagnetic switching knob is further provided on one side of the top of the electromagnetic pilot valve, and the mechanical / electromagnetic switching knob is used to switch between mechanical control and electromagnetic control.

[0017] Beneficial effects of the present invention:

[0018] 1. This large-flow unloading valve structure based on pilot adaptive control ensures the efficient operation of the hydraulic system under different working conditions by setting up four fluid circuits that work together. First, the main supply fluid circuit provides stable pressure through a one-way valve to prevent backflow, thereby improving fluid supply efficiency and system stability. The fluid circuit that controls the action of the ejector rod automatically maintains the pressure balance of the pilot valve core through high-pressure liquid to prevent malfunction or response delay, thereby enhancing the control accuracy of the system. The pressure-maintaining control fluid circuit keeps the main valve closed through high-pressure liquid to avoid liquid loss caused by vibration or loosening, thereby ensuring long-term stable operation of the system. The unloading return fluid circuit quickly guides the liquid backflow when the pressure reaches the threshold, thereby preventing overload, reducing energy consumption and extending equipment life, thereby improving the response speed, stability and control accuracy of the system, and effectively improving the efficiency and reliability of the hydraulic system.

[0019] 2. This large-flow unloading valve structure based on pilot adaptive control is equipped with a ceramic ball and a guide sleeve. The ceramic ball adopts a line sealing method to cooperate with the pilot valve seat to increase the contact area, reduce the impact of high-pressure liquid on the valve core, and prevent the sealing surface stress from increasing sharply, thereby improving the sealing reliability and the working life of the system. When the pressure changes, the push rod moves stably and the spring guide rod provides reverse pressure to ensure the reliable execution of the pilot valve closing or unloading function. In addition, the ceramic ball guide sleeve ensures the smooth movement of the ceramic ball, avoids the offset caused by fluid impact, reduces pressure fluctuations, and improves control accuracy. The adjustment sleeve and the set screw cooperate to allow the operator to accurately adjust the preload force of the spring guide rod, flexibly respond to the needs of different working conditions, and ensure the precise adjustment of the valve opening pressure, thereby optimizing the stability, response speed and control accuracy of the hydraulic system and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the unloading valve in operation state of the present invention;

[0023] Figure 3 This is a schematic diagram of the internal planar structure of the main valve body of the present invention;

[0024] Figure 4 This is a schematic diagram of the cross-sectional structure of the main valve body of the present invention;

[0025] Figure 5 Schematic diagram of the internal cross-sectional structure of the mechanical pilot valve of the present invention;

[0026] Figure 6 For the present invention Figure 5 The enlarged structural diagram at point I is shown in the figure.

[0027] The following are marked in the figure:

[0028] 1. Main valve body; 2. Mechanical pilot valve; 3. Adjusting screw; 4. Solenoid pilot valve; 5. Mechanical / electromagnetic switching knob; 6. Pilot filter; 7. Main valve sleeve; 8. Main valve seat; 9. Main valve spring; 10. Main valve spool; 11. Check valve spring; 12. Check valve spool; 13. Check valve guide sleeve; 14. High-pressure liquid supply channel; 15. Pump discharge channel; 16. Unloading return channel; 17. First high-pressure pipe; 18. Second high-pressure pipe; 19. Pilot valve plug; 20. Push rod; 21. Push rod guide sleeve; 22. Pilot valve seat; 23. First ceramic ball guide sleeve; 24. Adjusting screw sleeve; 25. Set screw; 26. Spring guide rod; 27. Second ceramic ball guide sleeve; 28. Third ceramic ball guide sleeve; 29. ​​Ceramic ball; 30. Third high-pressure pipe. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0030] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0031] like Figures 1 to 6As shown, a large flow unloading valve structure based on pilot adaptive control includes a main valve body 1, two main valve seats 8 are provided on the internal top of the main valve body 1, and a main valve spool 10 is provided on each of the two main valve seats 8. Two one-way valve guide sleeves 13 are provided on the internal bottom of the main valve body 1, and a one-way valve spool 12 is provided on each of the two one-way valve guide sleeves 13. The one-way valve spool 12 is provided below the main valve spool 10; a mechanical pilot valve 2 is provided at one end of the main valve body 1 and is connected to the main valve spool 10 through a fluid channel to control the opening and closing of the main valve spool 10 when the pressure of the hydraulic system rises. The internal of the mechanical pilot valve 2 A pilot valve core is provided at the top of the electromagnetic pilot valve 2; an electromagnetic pilot valve 4, which is provided at the top of one side of the mechanical pilot valve 2 and is connected to the main valve core 10 through a fluid channel to adjust the state of the main valve core 10 under the control of an external electrical signal; a pilot filter 6, which is provided at the bottom of one side of the mechanical pilot valve 2, and is used to filter the high-pressure liquid entering the electromagnetic pilot valve 4 or the inside of the mechanical pilot valve 2 to ensure stable operation of the system, wherein a mechanical / electromagnetic switching knob 5 is also provided on one side of the top of the electromagnetic pilot valve 4, and the mechanical / electromagnetic switching knob 5 is used to switch between mechanical control and electromagnetic control;

[0032] When the hydraulic system is operating, high-pressure liquid enters the main valve body 1 and simultaneously acts on the mechanical pilot valve 2 and the solenoid pilot valve 4. When the hydraulic system needs to maintain pressure, the main valve spool 10 remains closed under the control of the pilot valve spool, and the liquid flows to the working port, ensuring normal operation of the equipment. When the system reaches the set pressure limit, if it is in mechanical mode, the mechanical pilot valve 2 will respond to the pressure change and open the pilot channel, releasing the pressure above the main valve spool 10, causing the main valve spool 10 to move upward to achieve unloading. If it is in solenoid mode, the solenoid pilot valve 4 is controlled to open by an external electrical signal, directly changing the pressure state above the main valve spool 10, causing the main valve spool 10 to open and unload. The pilot filter 6 continues to operate throughout the process, filtering impurities from the high-pressure liquid and ensuring the stable operation of the electromagnetic and mechanical control systems. The mechanical / electromagnetic switching knob 5 can be used to select whether to control the unloading process in mechanical mode or electromagnetic mode to adapt to different working requirements. The addition of the mechanical / electromagnetic switching knob 5 enables the system to switch between automatic control and passive control, improving its applicability and adapting to different working conditions.

[0033] like Figure 1 、 Figure 4 As shown, two main valve springs 9 are provided at the top end of the inner part of the main valve body 1, and the bottom ends of the two main valve springs 9 are fixedly connected to one side of the main valve core 10 respectively. Two one-way valve springs 11 are provided in the middle part of the main valve body 1, and the other ends of the two one-way valve springs 11 are respectively embedded in one side of the two one-way valve cores 12. Two main valve sleeves 7 that are compatible with the main valve cores 10 are provided on the top surface of the main valve body 1;

[0034] When the hydraulic system is in a high-pressure liquid supply state, the main valve spring 9 ensures that the main valve spool 10 maintains its initial closed state, and the high-pressure liquid enters the working port through the one-way valve spool 12. The one-way valve spring 11 also provides additional sealing force to prevent backflow. When the system reaches the unloading condition, the pilot valve releases the high-pressure liquid on the upper part of the main valve spool, so that the reset force of the main valve spring 9 is overcome, and the main valve spool 10 moves up to open the unloading channel, and the liquid flows back to the return oil tank to achieve unloading. When the pressure drops below the set value, the main valve spring 9 pushes the main valve spool 10 to move down, so that the main valve spool 10 re-closes the liquid supply channel, and the hydraulic system resumes the pressure supply state. During the whole process, the main valve sleeve 7 ensures the smooth sliding of the main valve spool 10, reduces friction, and improves response speed and system stability.

[0035] like Figure 1 、 Figure 5 、 Figure 6 As shown, the pilot valve core includes a pilot valve screw plug 19 arranged on one side of the mechanical pilot valve 2, a push rod guide sleeve 21 is provided on one side of the pilot valve screw plug 19, a push rod 20 is slidably installed inside the push rod guide sleeve 21, a pilot valve seat 22 is provided on one side of the push rod guide sleeve 21, a first ceramic ball guide sleeve 23 is provided on one side of the pilot valve seat 22, a ceramic ball 29 is provided inside the first ceramic ball guide sleeve 23, a spring guide rod 26 is provided on the other side of the mechanical pilot valve 2, and a second ceramic ball guide sleeve 26 is also provided on the upper and lower sides of the spring guide rod 26. 7. A third ceramic ball guide sleeve 28 is further provided on the inner side of the two second ceramic ball guide sleeves 27. An adjusting screw sleeve 24 is provided on the side of the main valve body 1 away from the pilot valve plug 19. A set screw 25 is installed on the internal thread of the adjusting screw sleeve 24. One side of the set screw 25 is against the spring guide rod 26. An adjusting screw 3 is also provided on one side of the mechanical pilot valve 2. One side of the set screw 25 is fixedly connected to the adjusting screw 3. One side of the adjusting screw 3 is set to an inner hexagon. The sealing method of the first ceramic ball guide sleeve 23 and the ceramic ball 29 is set to a line seal.

[0036] When the pressure in the hydraulic system rises, high-pressure liquid enters the interior of the mechanical pilot valve 2, and exerts a force through the pilot valve seat 22, so that the ceramic ball 29 is in a sealed state to prevent liquid leakage. At this time, the push rod 20 remains stable in the push rod 20 guide sleeve, and the spring guide rod 26 provides reverse pressure to ensure that the pilot valve is in a closed state. When the hydraulic system needs to be unloaded, the pressure change pushes the push rod 20 to move backward, causing the ceramic ball 29 to deviate from the sealing position. The high-pressure liquid enters the reflux channel through the first ceramic ball 29, causing the main valve core to lose its upper pressure-maintaining function, thereby opening the unloading valve and realizing system unloading. During this process, the cooperation between the set screw 25 and the adjusting screw sleeve 24 allows the operator to accurately adjust the preload force of the spring guide rod 26, thereby adjusting the valve opening pressure to meet the needs of different working conditions;

[0037] Moreover, the sealing method of the ceramic ball 29 and the pilot valve seat 22 is line sealing. The spherical surface is in contact with the high-pressure liquid, which greatly increases the contact area and reduces the impact of the high-pressure liquid on the valve core. When the high-pressure liquid impacts and opens the ceramic ball 29, the high-pressure liquid passes along the spherical surface, and the contact area will not become smaller, thereby preventing the stress of the sealing surface from increasing rapidly. The ceramic ball 29 passes through the ceramic ball 29 guide sleeve, and the movement trajectory is smooth, which can maintain a smaller pressure fluctuation range under high-pressure conditions and stabilize the pressure.

[0038] like Figure 2 、 Figure 3 As shown, a high-pressure liquid supply channel 14, a pump discharge channel 15, and an unloading return liquid channel 16 are further provided on one side of the main valve body 1. The high-pressure liquid supply channel 14 is located at the bottom of the main valve body 1 and is arranged above the one-way valve. A high-pressure liquid supply port is provided on one side of the high-pressure liquid supply channel 14. The unloading return liquid channel 16 is located at the top of the main valve body 1. The unloading return liquid channel 16 is connected to the two main valve spools 10. An unloading return liquid port is provided on one side of the unloading return liquid channel 16. The pump discharge channel 15 is arranged between the high-pressure liquid supply channel 14 and the unloading return liquid channel 16. A pump discharge port is provided on one side of the pump discharge channel 15.

[0039] When the hydraulic system is in the liquid supply state, high-pressure liquid enters the main valve body 1 from the high-pressure liquid supply channel 14 and flows to the actuator through the main valve spool 10, providing a stable working pressure. When the system pressure reaches the set value, if unloading is required, the main valve spool 10 is opened under the action of the pilot control, allowing the high-pressure liquid to flow into the unloading return port through the unloading return channel 16, thereby releasing the pressure and ensuring the safety of the system. When the unloading is completed, the main valve spool 10 is reset, blocking the unloading return channel 16, and the system re-establishes pressure. At the same time, the pump discharge channel 15 ensures that the discharged liquid from the pump can flow smoothly into the main valve and further into the system, preventing the accumulation of liquid in the pump or the fluctuation of the liquid flow from affecting the action of the main valve spool, so that the entire hydraulic circuit remains stable.

[0040] A first high-pressure pipe 17 is provided on one side of the high-pressure liquid supply channel 14, and the other end of the first high-pressure pipe 17 is connected to the pilot valve core inside the mechanical pilot valve 2, and the first high-pressure pipe 17 is arranged at the rear of the push rod 20; a second high-pressure pipe 18 is provided on one side of the pump discharge channel 15, and the second high-pressure pipe 18 is connected to the main valve core 10 after returning to the pilot valve core through the pilot filter 6, and the second high-pressure pipe 18 is first connected to the main valve core 10 through the main valve sleeve 7; a third high-pressure pipe 30 is provided on one side of the unloading return liquid channel 16, and the other end of the third high-pressure pipe 30 is connected to the rear of the pilot valve core. The diameters of the first high-pressure pipe 17, the second high-pressure pipe 18, and the third high-pressure pipe 30 are all set to 3mm;

[0041] When the hydraulic system is started, the high-pressure emulsion flows along the first fluid path (main fluid path) through the high-pressure fluid supply channel 14 and enters the working port through the one-way valve, providing stable pressure for the hydraulic support. This main fluid path is the core power source of the hydraulic system, ensuring the normal operation of the hydraulic actuators. At the same time, the one-way valve is used to prevent the backflow of high-pressure fluid, thereby improving the fluid supply efficiency and system stability.

[0042] At the same time, the second hydraulic circuit (the hydraulic circuit that controls the action of the push rod 20) delivers high-pressure liquid to the interior of the mechanical pilot valve 2 through the first high-pressure pipe 17, and then enters the rear part of the push rod 20 of the pilot valve core through a 3mm small hole, ensuring that the push rod 20 always applies force to the pilot valve core to keep it in a balanced state. The advantage of this is that it can automatically maintain the pressure balance of the pilot valve core during system operation, preventing malfunction or response delay caused by pressure fluctuations, thereby improving the control accuracy and stability of the entire hydraulic system;

[0043] When the system is in the pressure-maintaining state, the third fluid circuit (pressure-maintaining control fluid circuit) guides the high-pressure fluid from the pump into the pilot valve core through the second high-pressure pipe 18, and then enters the upper part of the main valve core 10 through the main valve sleeve 7, forming a downward thrust, pressing the main valve core 10 against the main valve seat, keeping the main valve closed. The advantage of this pressure-maintaining control mechanism is that it ensures that the high-pressure state of the system can be maintained for a long time, avoiding accidental loss of hydraulic oil due to vibration or loosening of the main valve core 10, and ensuring a quick response when fluid supply is needed;

[0044] When the system enters the unloading stage, the fourth liquid circuit (unloading return liquid circuit) begins to play a role. When the system pressure reaches the preset unloading threshold, the pilot valve core opens, and the high-pressure liquid in the third high-pressure pipe 30 is guided to the unloading return liquid channel 16, which causes the pressure on the upper part of the main valve core 10 to drop rapidly, losing the pressure-maintaining effect, and then moves upward, opening the return channel, so that the excess high-pressure liquid directly returns to the oil tank. The advantage of this design is that it can quickly respond to unloading needs, avoid high-pressure overload damage to the system, and enable the pump to enter a low-load operation state, improve energy utilization efficiency, and extend equipment life.

[0045] The entire workflow relies on the coordination of four hydraulic circuits to achieve hydraulic system fluid supply, pressure maintenance, unloading and pressure balance, ensuring the system's stability, response speed and control accuracy under different working conditions;

[0046] Therefore, when the external hydraulic support stops using liquid, the liquid pressure in the pipeline system will rise immediately, the mechanical pilot valve 2 will open, the main valve will not be able to maintain pressure, the liquid will be directly returned to the tank by the pump, and the pump will maintain high pressure and continue to unload (such as Figure 2 Middle BB state);

[0047] When the hydraulic support starts to use liquid again or the pressure drops due to system leakage, the mechanical pre-pilot valve core will close, the main valve will start to maintain pressure again, the main valve core will move down until it is closed, and the high-pressure liquid will push open the one-way valve to supply liquid to the system again (such as Figure 2 medium AA status).

[0048] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0049] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A large flow unloading valve structure based on pilot adaptive control, characterized in that: include: A main valve body (1), wherein two main valve seats (8) are provided on the top of the interior of the main valve body (1), and a main valve core (10) is provided on each of the two main valve seats (8); two one-way valve guide sleeves (13) are provided on the bottom of the interior of the main valve body (1), and a one-way valve core (12) is provided on each of the two one-way valve guide sleeves (13), and the one-way valve core (12) is provided below the main valve core (10); a mechanical pilot valve (2), the mechanical pilot valve (2) being arranged at one end of the main valve body (1) and being in communication with the main valve core (10) through a fluid passage so as to control the opening and closing of the main valve core (10) when the pressure of the hydraulic system rises, and a pilot valve core being arranged inside the mechanical pilot valve (2); an electromagnetic pilot valve (4), the electromagnetic pilot valve (4) being arranged on a top side of the mechanical pilot valve (2) and being in communication with the main valve core (10) through a fluid channel so as to adjust the state of the main valve core (10) under the control of an external electrical signal; A pilot filter (6), the pilot filter (6) being arranged at the bottom of one side of the mechanical pilot valve (2), the pilot filter (6) being used to filter the high-pressure liquid entering the electromagnetic pilot valve (4) or the mechanical pilot valve (2) to ensure stable operation of the system; Two main valve springs (9) are provided at the top end of the inner portion of the main valve body (1), the bottom ends of the two main valve springs (9) are fixedly connected to one side of the main valve core (10), two one-way valve springs (11) are provided at the middle portion of the main valve body (1), the other ends of the two one-way valve springs (11) are embedded in one side of the two one-way valve cores (12), and two main valve sleeves (7) adapted to the main valve cores (10) are provided on the top surface of the main valve body (1); A high-pressure liquid supply channel (14), a pump liquid discharge channel (15), and an unloading liquid return channel (16) are further provided on one side of the main valve body (1). The high-pressure liquid supply channel (14) is located at the bottom of the main valve body (1) and is arranged above the one-way valve guide sleeve (13). A high-pressure liquid supply port is provided on one side of the high-pressure liquid supply channel (14). The unloading liquid return channel (16) is located at the top of the main valve body (1). The unloading liquid return channel (16) is connected to the two main valve cores (10). An unloading liquid return port is provided on one side of the unloading liquid return channel (16). The pump liquid discharge channel (15) is arranged between the high-pressure liquid supply channel (14) and the unloading liquid return channel (16). A pump liquid discharge port is provided on one side of the pump liquid discharge channel (15).

2. The large flow unloading valve structure based on pilot adaptive control according to claim 1 is characterized in that: The pilot valve core includes a pilot valve plug (19) provided on one side of the mechanical pilot valve (2), a push rod guide sleeve (21) provided on one side of the pilot valve plug (19), a push rod (20) slidably mounted inside the push rod guide sleeve (21), a pilot valve seat (22) provided on one side of the push rod guide sleeve (21), a first ceramic ball guide sleeve (23) provided on one side of the pilot valve seat (22), a ceramic ball (29) provided inside the first ceramic ball guide sleeve (23), a spring guide rod (26) provided on the other side of the mechanical pilot valve (2), and the upper and lower sides of the spring guide rod (26) are also provided. A second ceramic ball guide sleeve (27) is provided, and a third ceramic ball guide sleeve (28) is further provided on the inner side of the two second ceramic ball guide sleeves (27). An adjusting screw sleeve (24) is provided on the side of the main valve body (1) away from the pilot valve plug (19). A set screw (25) is installed on the internal thread of the adjusting screw sleeve (24). One side of the set screw (25) is against the spring guide rod (26). An adjusting screw (3) is further provided on one side of the mechanical pilot valve (2). One side of the set screw (25) is fixedly connected to the adjusting screw (3), and one side of the adjusting screw (3) is set as a hexagonal socket.

3. The large flow unloading valve structure based on pilot adaptive control according to claim 2 is characterized in that: The sealing method of the first ceramic ball guide sleeve (23) and the ceramic ball (29) is both configured as a line seal.

4. The large flow unloading valve structure based on pilot adaptive control according to claim 3 is characterized in that: A first high-pressure pipe (17) is provided on one side of the high-pressure liquid supply channel (14), the other end of the first high-pressure pipe (17) is connected to the pilot valve core inside the mechanical pilot valve (2), and the first high-pressure pipe (17) is provided at the rear of the push rod (20).

5. The large flow unloading valve structure based on pilot adaptive control according to claim 4 is characterized in that: A second high-pressure pipe (18) is provided on one side of the pump discharge channel (15). The second high-pressure pipe (18) flows back into the pilot valve core through the pilot filter (6) and then communicates with the main valve core (10). The second high-pressure pipe (18) is first connected to the main valve core (10) through the main valve sleeve (7).

6. The large flow unloading valve structure based on pilot adaptive control according to claim 5 is characterized in that: A third high-pressure pipe (30) is provided on one side of the unloading return liquid channel (16), and the other end of the third high-pressure pipe (30) is connected to the rear of the pilot valve core. The diameters of the first high-pressure pipe (17), the second high-pressure pipe (18), and the third high-pressure pipe (30) are all set to 3 mm.

7. The large flow unloading valve structure based on pilot adaptive control according to claim 6 is characterized in that: A mechanical / electromagnetic switching knob (5) is also provided on one side of the top of the electromagnetic pilot valve (4), and the mechanical / electromagnetic switching knob (5) is used to switch between mechanical control and electromagnetic control.

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