Large-flow unloading valve structure based on pilot self-adaptive control

Abstract

The invention relates to the technical field of unloading valves, in particular to a high-flow unloading valve structure based on pilot self-adaptive control, which comprises a main valve body, two main valve seats are arranged at the top of the interior of the main valve body, main valve cores are arranged on the two main valve seats, two one-way valve guide sleeves are arranged at the bottom of the interior of the main valve body, and two one-way valve guide sleeves are arranged at the bottom of the interior of the main valve body. The two one-way valve guide sleeves are each provided with a one-way valve element, and the one-way valve elements are arranged below the main valve element. The mechanical pilot valve is arranged at one end of the main valve body; and the electromagnetic pilot valve is arranged at the top of one side of the mechanical pilot valve. Compared with the prior art, through mutual cooperation of the four liquid paths, long-term stable operation of the system is ensured, overload is prevented, energy consumption is reduced, the service life of equipment is prolonged, then the response speed, stability and control precision of the system are improved, and the efficiency and reliability of the hydraulic system are effectively improved.

Description

Technical Field

[0001] The 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 wire 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, which effectively reduces 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 circuit to automatically maintain the pressure balance of the pilot valve core, and the pressure fluctuation The movement may easily lead to malfunction or response delay of the valve core, thereby affecting the control accuracy and stability of the system, reducing the response speed of the hydraulic actuator, and there is no special reflux fluid 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, in the unloading valve, only ball seal and spring reset are used, 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 purpose, the present invention provides a large flow unloading valve structure based on pilot adaptive control, including a main valve body, two main valve seats are arranged on the top of the main valve body, and the two main valve seats are both provided with a main valve core, and two one-way valve guide sleeves are arranged on the bottom of the main valve body, and the two one-way valve guide sleeves are both provided with a one-way valve core, and the one-way valve core is arranged below the main valve core; A mechanical pilot valve, which is arranged at one end of the main valve body and communicates with the main valve core through a fluid channel to control the opening and closing of the main valve core when the pressure of the hydraulic system rises, and a pilot valve core is arranged inside the mechanical pilot valve; An electromagnetic pilot valve, which is arranged at the top of one side of the mechanical pilot valve and is connected to the main valve core through a fluid channel to adjust the state of the main valve core under the control of an external electrical signal; A pilot filter is arranged at the bottom of one side of the mechanical pilot valve, and 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.

[0006] 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.

[0007] 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 communicated 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.

[0008] 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 arranged 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 arranged on one side of the pilot valve seat, a first ceramic ball guide sleeve is arranged on one side of the pilot valve seat, a ceramic ball is arranged inside the first ceramic ball guide sleeve, a spring guide rod is arranged on the other side of the mechanical pilot valve, a second ceramic ball guide sleeve is also arranged on the upper and lower sides of the spring guide rod, and a third ceramic ball guide sleeve is also arranged on the inner side of the two second ceramic ball guide sleeves, an adjusting screw sleeve is arranged on the side of the main valve body away from the pilot valve plug, a set screw is threadedly installed on the inner side of the adjusting screw sleeve, one side of the set screw is abutted against the spring guide rod, an adjusting screw is also arranged 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 arranged as a hexagon socket.

[0009] Preferably, the sealing method of the first ceramic ball guide sleeve and the ceramic ball is set to be line sealing.

[0010] 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.

[0011] Preferably, a second high-pressure pipe is provided on one side of the pump discharge channel. The second high-pressure pipe is connected to the main valve core after returning to the pilot valve core through the pilot filter. The second high-pressure pipe is first connected to the main valve core through the main valve sleeve.

[0012] Preferably, a third high-pressure pipe is provided on one side of the unloading return liquid channel, the other end of the third high-pressure pipe is connected to the rear of the pilot valve core, and 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.

[0013] 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.

[0014] Beneficial effects of the present invention: 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 fluid supply 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 push rod automatically maintains the pressure balance of the pilot valve core through high-pressure liquid to prevent misoperation 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 and stable operation of the system. The unloading return fluid circuit quickly guides the liquid to reflux 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.

[0015] 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 cooperates with the pilot valve seat in a wire sealing manner to increase the contact area, reduce the impact of high-pressure liquid on the valve core, and prevent a sharp increase in sealing surface stress, thereby improving the reliability of the seal 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 cooperation between the adjusting screw sleeve and the set screw allows 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

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the structure of the unloading valve in operation state of the present invention; Figure 3 This is a schematic diagram of the internal planar structure of the main valve body of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the main valve body of the present invention; Figure 5 It is a schematic diagram of the internal cross-sectional structure of the mechanical pilot valve of the present invention; Figure 6For the present invention Figure 5 The enlarged structural diagram at point I in the middle.

[0018] The markings in the figure are: 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 core; 11. Check valve spring; 12. Check valve core; 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

[0019] 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 in conjunction with specific embodiments.

[0020] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be 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 described object changes, the relative positional relationship may also change accordingly.

[0021] 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 arranged on the top of the main valve body 1, and main valve cores 10 are arranged on the two main valve seats 8, and two one-way valve guide sleeves 13 are arranged on the bottom of the main valve body 1, and one-way valve cores 12 are arranged on the two one-way valve guide sleeves 13, and the one-way valve cores 12 are arranged below the main valve cores 10; a mechanical pilot valve 2, which is arranged at one end of the main valve body 1 and is connected to the main valve core 10 through a fluid channel to control the opening and closing of the main valve core 10 when the pressure of the hydraulic system rises, and the inner A pilot valve core is provided at the top of one side of the mechanical 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 the pilot filter 6 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; When the hydraulic system is running, high-pressure liquid enters the main valve body 1 and acts on the mechanical pilot valve 2 and the electromagnetic pilot valve 4 at the same time. When the hydraulic system needs to maintain pressure, the main valve core 10 remains in a closed state under the control of the pilot valve core, and the liquid flows to the working port to ensure the normal operation of the equipment. When the system reaches the set pressure upper limit, if it is in mechanical mode, the mechanical pilot valve 2 will respond to the pressure change and open the pilot channel to release the pressure on the upper part of the main valve core 10, and the main valve core 10 moves up to achieve unloading; if it is in electromagnetic mode, the electromagnetic pilot valve 4 is opened by external electrical signal control, directly changing the pressure state on the upper part of the main valve core 10, causing the main valve core 10 to open for unloading. The pilot filter 6 continues to work during the whole process to filter impurities in the high-pressure liquid to ensure the stable operation of the electromagnetic and mechanical control systems. Through the mechanical / electromagnetic switching knob 5, you can choose 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, improves applicability, and adapts to different working conditions.

[0022] like Figure 1 , Figure 4 As shown, two main valve springs 9 are arranged at the top of the inner part of the main valve body 1, and the bottom ends of the two main valve springs 9 are respectively fixedly connected to one side of the main valve core 10, and two one-way valve springs 11 are arranged 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 and installed on one side of the two one-way valve cores 12, and two main valve sleeves 7 adapted to the main valve cores 10 are arranged on the top surface of the main valve body 1; When the hydraulic system is in a high-pressure fluid supply state, the main valve spring 9 ensures that the main valve core 10 maintains an initial closed state, and the high-pressure liquid enters the working port through the one-way valve core 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 core, so that the reset force of the main valve spring 9 is overcome, and the main valve core 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 core 10 to move down, so that the main valve core 10 re-closes the fluid 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 core 10, reduces friction, and improves the response speed and system stability.

[0023] 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 arranged 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 arranged on one side of the push rod guide sleeve 21, a first ceramic ball guide sleeve 23 is arranged on one side of the pilot valve seat 22, a ceramic ball 29 is arranged inside the first ceramic ball guide sleeve 23, a spring guide rod 26 is arranged on the other side of the mechanical pilot valve 2, and a second ceramic ball guide sleeve 26 is also arranged on the upper and lower sides of the spring guide rod 26. 7. A third ceramic ball guide sleeve 28 is also 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 screw 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. When the pressure of the hydraulic system rises, the 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 guide sleeve of the push rod 20, 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, so that the ceramic ball 29 deviates from the sealing position, and the high-pressure liquid enters the reflux channel through the first ceramic ball 29, causing the main valve core to lose the upper pressure-maintaining function, thereby opening the unloading valve and realizing system unloading. In this process, the cooperation of 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; 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 does not become smaller, thereby preventing the stress on 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.

[0024] like Figure 2 , Figure 3 As shown, a high-pressure liquid supply channel 14, a pump liquid discharge channel 15, and an unloading liquid return channel 16 are also 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 liquid return channel 16 is located at the top of the main valve body 1. The unloading liquid return channel 16 is connected with 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. When the hydraulic system is in the liquid supply state, the 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 core 10, providing a stable working pressure. When the system pressure reaches the set value, if unloading is required, the main valve core 10 is opened under the action of the pilot control, so that the high-pressure liquid flows into the unloading return port through the unloading return channel 16 to achieve pressure release and ensure system safety. When the unloading is completed, the main valve core 10 is reset to block 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 of the pump can flow smoothly into the main valve and further enter 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 core, so that the entire hydraulic circuit remains stable; 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, and 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; When the hydraulic system is started, the high-pressure emulsion flows along the first fluid path (main fluid supply path) through the high-pressure fluid supply channel 14 and enters the working port through the one-way valve to provide stable pressure for the hydraulic support. This main fluid supply path is the core power source of the hydraulic system, ensuring the normal operation of the hydraulic actuator. At the same time, the one-way valve is used to prevent the high-pressure fluid from flowing back, thereby improving the fluid supply efficiency and system stability. At the same time, the second fluid circuit (the fluid circuit controlling the action of the push rod 20) delivers high-pressure liquid to the inside of the mechanical pilot valve 2 through the first high-pressure pipe 17, and then enters the rear 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, prevent malfunction or response delay caused by pressure fluctuations, and thus improve the control accuracy and stability of the entire hydraulic system; When the system is in a pressure-maintaining state, the third fluid circuit (pressure-maintaining control fluid circuit) guides the high-pressure liquid 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, and 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 rapid response when fluid supply is needed; When the system enters the unloading stage, the fourth liquid circuit (unloading return liquid circuit) begins to function. 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 to open 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 and avoid high-pressure overload damage to the system. At the same time, it enables the pump to enter a low-load operating state, improve energy efficiency, and extend equipment life. 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 stability, response speed and control accuracy of the system under different working conditions; 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 cannot 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 operation (such as Figure 2 Middle BB state); 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 2medium AA status).

[0025] A person 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. Under the concept 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.

[0026] 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 in 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 arranged at the top of the main valve body (1), and a main valve core (10) is arranged on each of the two main valve seats (8); two one-way valve guide sleeves (13) are arranged at the bottom of the main valve body (1), and a one-way valve core (12) is arranged on each of the two one-way valve guide sleeves (13); and the one-way valve core (12) is arranged 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 connected to 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 at the top of one side of the mechanical pilot valve (2) and being connected to 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.

2. The large flow unloading valve structure based on pilot adaptive control according to claim 1 is characterized in that: Two main valve springs (9) are arranged at the inner top of the main valve body (1), and the bottom ends of the two main valve springs (9) are respectively fixedly connected to one side of the main valve core (10). Two one-way valve springs (11) are arranged in the middle 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) adapted to the main valve cores (10) are arranged on the top surface of the main valve body (1).

3. The large flow unloading valve structure based on pilot adaptive control according to claim 2 is characterized in that: A high-pressure liquid supply channel (14), a pump liquid discharge channel (15), and an unloading liquid return channel (16) are also 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).

4. The large flow unloading valve structure based on pilot adaptive control according to claim 3 is characterized in that: The pilot valve core comprises a pilot valve screw plug (19) arranged on one side of the mechanical pilot valve (2); a push rod guide sleeve (21) is arranged on one side of the pilot valve screw plug (19); a push rod (20) is slidably mounted inside the push rod guide sleeve (21); a pilot valve seat (22) is arranged on one side of the push rod guide sleeve (21); a first ceramic ball guide sleeve (23) is arranged on one side of the pilot valve seat (22); a ceramic ball (29) is arranged inside the first ceramic ball guide sleeve (23); a spring guide rod (26) is arranged on the other side of the mechanical pilot valve (2); 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 screw plug (19); a set screw (25) is installed on the inner thread of the adjusting screw sleeve (24); one side of the set screw (25) abuts 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 provided with a hexagon socket.

5. The large flow unloading valve structure based on pilot adaptive control according to claim 4 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.

6. The large flow unloading valve structure based on pilot adaptive control according to claim 5 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).

7. The large flow unloading valve structure based on pilot adaptive control according to claim 6 is characterized in that: A second high-pressure pipe (18) is provided on one side of the pump discharge passage (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) first communicates with the main valve core (10) through the main valve sleeve (7).

8. The large flow unloading valve structure based on pilot adaptive control according to claim 7 is characterized in that: A third high-pressure pipe (30) is provided on one side of the unloading liquid return channel (16); 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.

9. The large flow unloading valve structure based on pilot adaptive control according to claim 8 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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