Explosion-proof valve and control method thereof

Abstract

The invention discloses an anti-explosion valve and a control method thereof in the technical field of engineering machinery, and aims to solve the problems of complex structure, inconvenience in maintenance and low reliability of the anti-explosion valve in the prior art. The pilot valve comprises a second oil port communicated with a main oil way, a first oil port communicated with an oil tank, a cone valve and a pilot valve element, the cone valve is provided with a first cavity and a second cavity, and the first cavity is communicated with the main oil way; the position of the pilot valve element is switched according to whether oil is supplied by the pilot oil port or not, so that a second cavity of the cone valve is selectively connected to the first oil port for pressure relief, the pressure difference between the second cavity and the first cavity is controlled, and the cone valve is made to move; when the pressure of the second cavity is relieved, the pilot valve element is further communicated with an oil way, passing through the pilot valve element, of the first oil port and the second oil port so as to assist unloading work of a main oil way. The pilot oil way drives the main valve element to act, indirect control over the high-pressure oil way is achieved, the size of the installation space is effectively reduced, maintainability is enhanced, and safety and reliability are achieved.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof valve technology, and in particular to an explosion-proof valve and its control method. Background Technology

[0002] In hydraulic systems of construction machinery, explosion-proof valves are critical devices for ensuring the safety of equipment and personnel. Primarily installed on the hydraulic cylinder circuits, their core function is to quickly cut off the oil circuit to prevent accidental load drops when a pipeline ruptures or other malfunctions cause a sudden pressure release. However, existing explosion-proof valve structures generally suffer from the following drawbacks: First, in low-temperature environments, the viscosity of the hydraulic oil increases significantly, leading to delayed valve opening and slow cylinder response, severely impacting operational efficiency. Second, the coordination of complex actions is poor. In traditional designs, the valve opening pressure is highly correlated with the load; when excavators perform coordinated operations involving multiple mechanisms such as the boom and stick, uneven pressure distribution can easily cause action jamming. Summary of the Invention

[0003] The purpose of this invention is to provide an explosion-proof valve and its control method to solve the technical problems of complex structure, inconvenient maintenance and low reliability of explosion-proof valves in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides an explosion-proof valve, comprising a second oil port connected to a main oil circuit, a first oil port connected to an oil tank, a cone valve, and a pilot valve core, wherein the cone valve has a first chamber and a second chamber, and the first chamber is connected to the main oil circuit.

[0006] The pilot valve core switches positions according to the oil supply status of the pilot port to selectively connect the second chamber of the cone valve to the first port for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber and causing the cone valve to move.

[0007] When the second chamber is pressurized, the cone valve is in the first working position, and the cone valve is in contact with the mounting base, cutting off the connection between the first oil port and the second oil port, and the main oil circuit is in the pressure building working position; when the second chamber is depressurized, the cone valve is in the second working position, and the cone valve is away from the mounting base, connecting the oil circuit of the first oil port and the second oil port through the mounting base, and the main oil circuit switches to the unloading state.

[0008] When the pilot valve core is depressurized in the second chamber, it also connects the oil passages of the first oil port and the second oil port through the pilot valve core to assist the unloading work of the main oil passage.

[0009] The valve body drains oil through the second port connected to the main oil circuit. When the actuator is locked, the oil flows from the second port to the second chamber of the cone valve for pressurization, pushing the cone valve to the first working position to cut off the oil circuit connecting the first and second ports. At this time, the actuator cannot retract due to the explosion-proof valve being locked. When the actuator retracts, the pilot port supplies oil to the pilot valve core, switching the position of the valve core in the valve body to connect the oil circuit connecting the first and second ports through the pilot valve core. The oil flows in the first and second ports, the second chamber is depressurized, and the cone valve moves away from the first port to the second working position, connecting the oil circuit connecting the first and second ports through the mounting base, thus unloading the main oil circuit and ensuring the safe and stable retraction of the actuator.

[0010] Furthermore, the valve body is provided with a valve cavity, and the valve cavity is provided with a valve body valve core. The pilot valve core is located at the bottom of the valve body valve core. The valve body valve core and the pilot valve core pass through the first oil port and the second oil port, and are sealed with the valve cavity through the first valve sleeve and the second valve sleeve, respectively, so as to drive the valve body valve core to move through the pilot valve core, thereby realizing indirect control of the main oil circuit under high pressure.

[0011] The pilot valve core switches the working position of the valve body core under the coordinated action of the first valve sleeve and the second valve sleeve. It achieves the pressure relief function by selectively connecting the oil passage between the cone valve and the first oil port. The precise cooperation of the multi-stage valve sleeve ensures the accuracy of oil passage switching when the valve body core is displaced. At the same time, the cone valve quickly releases the system pressure, improving the dynamic response performance of the hydraulic circuit.

[0012] Furthermore, the area of ​​the second chamber is larger than the area of ​​the first chamber.

[0013] When the cone valve is in the first working position, because the area of ​​the second chamber is larger than that of the first chamber, the pressure in the second chamber is always greater than that in the first chamber. This ensures that the oil passage connecting the second port and the first port is not connected, maintains the pressure-building working position of the main oil passage, and improves the working stability of the actuator.

[0014] Furthermore, the valve body is connected to an overflow valve, which is connected between the cone valve and the oil tank.

[0015] When the pressure in the second chamber exceeds the preset threshold, the overflow valve opens to direct the oil to the unloading port and back to the oil tank, preventing mechanical failures such as oil pipe bursting and pump damage, while maintaining stable oil circuit pressure to avoid abnormal operation of the actuator.

[0016] Furthermore, the valve body has an oil discharge port on its side, and the spring chamber of the valve core and the overflow valve are both connected to the oil discharge port.

[0017] Regardless of whether the oil passage between the first and second oil ports is open, the main oil passage pressure remains stable. This is achieved through the pressure difference between the multiple chambers of the cone valve. Different pressure relief oil passages are selected according to the operating conditions to ensure that the main oil passage pressure remains constant.

[0018] Furthermore, the valve body core, the pilot valve core, and the cone valve are respectively connected to the valve body through a first sealing element, a second sealing element, and a third sealing element.

[0019] Multiple seals create a comprehensive seal between the valve body and the internal oil circuits, preventing oil leakage. This not only prevents the risk of explosion caused by the leakage of flammable media, but also avoids internal oil cross-contamination that could lead to pressure turbulence and failure of the explosion-proof function. It improves the dynamic response speed and adaptability to different operating conditions, reduces friction in the valve body, valve core, pilot valve core, and cone valve to ensure rapid pressure relief in case of overpressure, and maintains stable sealing under complex environments such as high and low temperatures and vibration. Furthermore, it reduces media loss and contamination, minimizes oil circuit failures, and extends the lifespan of seals and the overall lifespan of the explosion-proof valve, thereby reducing maintenance costs. This comprehensive approach ensures the safe and reliable operation of the explosion-proof valve, making it a core element in achieving its explosion-proof function and stable operation.

[0020] Secondly, the present invention also provides a control method for the explosion-proof valve described in any one of the above claims, the method comprising the following steps:

[0021] The position of the pilot valve core is switched according to the oil supply status of the pilot port to selectively connect the second chamber of the cone valve to the first port for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber and causing the cone valve to move.

[0022] When the cone valve is controlled to the first working position, the oil circuit is connected to the second chamber of the cone valve through the second oil port, so that the second chamber is pressurized; using the pressure difference between the first chamber and the second chamber, the cone valve is driven to move to the first working position to cut off the connection between the first oil port and the second oil port, so that the main oil circuit is in the pressure building working position;

[0023] When the cone valve is controlled to the second working position, the second chamber of the cone valve is connected to the first oil port by the reversal of the pilot valve core, so that the second chamber is depressurized; by using the pressure difference between the first chamber and the second chamber, the cone valve is driven to move to the second working position to connect the oil circuit of the first oil port and the second oil port through the mounting seat, so that the main oil circuit is in an unloaded state.

[0024] At the same time, when the cone valve is in the second working position, the pilot valve core connects the oil passages of the first and second oil ports through the pilot valve core to assist the unloading work of the main oil passage.

[0025] The control signal is determined by whether the pilot port supplies oil to the pilot valve core. By switching the pilot valve core, the pressure state of the second chamber in the cone valve is automatically changed. The pressure difference between the first and second chambers drives the cone valve to move, thereby automatically and accurately switching between the main oil circuit's pressure building and unloading states. In particular, during the unloading process, the opening of the pilot valve core drives the cone valve away from the valve body's mounting seat, simultaneously opening multiple connecting oil circuits between the first port and the second oil circuit, forming a dual unloading effect. This greatly optimizes the dynamic response speed and unloading reliability of the explosion-proof valve, ensuring that the actuator retracts stably and efficiently.

[0026] Furthermore, when the cone valve is in the first working position and the pilot port does not supply oil to the pilot valve core, if the pressure value in the second chamber exceeds the preset pressure value, the oil flows back to the oil tank through the overflow valve.

[0027] When the cone valve is in the first working position, the second chamber is pressurized. When the pressure exceeds the preset threshold, the overflow valve opens, leading the oil in the main oil circuit to the oil tank for unloading. This design ensures that even if the pilot valve core is not working, the explosion-proof valve can still dynamically adjust the system oil circuit pressure when the pipeline suddenly ruptures or the actuator needs to be retracted, thereby stably recovering the equipment and improving the safety and reliability of the system.

[0028] Compared with the prior art, the explosion-proof valve of the present invention achieves the following beneficial effects:

[0029] 1. This invention uses a pilot valve core to sense changes in the oil supply status and automatically switches the pressure balance between the two chambers of the cone valve, thereby precisely controlling the switching of the cone valve's operating position. This achieves reliable and automatic switching between the main oil circuit and the two states of maintaining pressure building and rapid unloading. In particular, during the unloading process, the pilot valve core not only drives the cone valve to move but also assists in connecting the unloading oil circuit, forming a dual unloading guarantee mechanism. This significantly improves the timeliness of the device's response and the unloading efficiency, ultimately ensuring that the actuator can retract quickly and smoothly.

[0030] 2. This invention adopts a hydraulic pilot control method. By rationally designing the structure of the pilot stage and the main oil circuit, and adding an overflow valve connected between the cone valve and the oil tank, the number of parts is reduced, the structure is simplified and the economy is improved. At the same time, it achieves dual safety protection after pipeline rupture. It can quickly cut off the main oil circuit to prevent the actuator load from falling, and can also achieve slow recovery operation of the equipment through pilot oil circuit control, which significantly improves the controllability and safety in emergency conditions.

[0031] 3. This invention can achieve unloading or oil priming functions by switching the oil circuit connection of the second oil port; when the second oil port is connected to a load, the pressure fluctuation frequency of the oil can be controlled by adjusting the cone valve, which can dynamically change the pressure of the load port, simulate working conditions such as vibration and crushing, and significantly improve the system's scalability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the cone valve of the explosion-proof valve in the first working position according to an embodiment of the present invention;

[0034] Figure 2 yes Figure 1 Structural principle diagram;

[0035] Figure 3 This is a schematic diagram of the cone valve of the explosion-proof valve in the second working position according to an embodiment of the present invention;

[0036] Figure 4 yes Figure 3 The structural principle diagram.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. First oil port; 2. Oil discharge port; 3. Pilot oil port; 4. Piston; 5. First valve sleeve; 6. Third seal; 7. Spring cavity; 8. Cone valve; 9. Second oil port; 10. Second valve sleeve; 11. Spring seat; 12. Valve core spring; 13. Valve body core; 14. First seal; 15. Valve body; 16. Relief valve; 301. Pilot valve core; 102. Mounting seat; 801. Transverse oil passage; 401. Second seal. Detailed Implementation

[0039] 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.

[0040] Example 1:

[0041] like Figure 1 As shown, this embodiment provides an explosion-proof valve, including a second oil port 9 connected to the main oil circuit, a first oil port 1 connected to the oil tank, a cone valve 8, and a pilot valve core 301. The cone valve 8 has a first chamber and a second chamber, and the first chamber is connected to the main oil circuit.

[0042] The pilot valve core 301 switches positions according to the oil supply status of the pilot port 3, selectively connecting the second chamber of the cone valve 8 to the first port 1 for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber, causing the cone valve 8 to move; the pressure difference between the first chamber and the second chamber is used to control the connection between the first port 1 and the second port 9 to open and close the oil circuit. Under the synergistic action of the pilot valve core 301, the cone valve 8 selectively connects different oil relief circuits to dynamically adjust the pressure of the main oil circuit and maintain the working stability of the system.

[0043] When the second chamber is pressurized, the cone valve 8 is in the first working position, and the cone valve 8 is in contact with the mounting seat 102 of the valve body 15, cutting off the connection between the first oil port 1 and the second oil port 9, and the main oil circuit is in the pressure building working position; when the second chamber is depressurized, the cone valve 8 is in the second working position, and the cone valve 8 is away from the mounting seat 102, connecting the oil circuit of the first oil port 1 and the second oil port 9 through the mounting seat 102, and the main oil circuit switches to the unloading state; when the actuator is locked, the second chamber is in the pressurized state, and the oil reaches the second chamber through the first chamber, pushing the cone valve 8 to move to the first working position to cut off the connection between the first oil port 1 and the second oil port 9; when the actuator retracts to depressurize the second chamber, the pressure in the first chamber gradually exceeds the pressure in the second chamber, and the cone valve 8 moves away from the mounting seat 102 to the second working position, and the oil at the second oil port 9 flows directly to the first oil port 1 for unloading.

[0044] When the second chamber is depressurized, the pilot valve core 301 also connects the first oil port 1 and the second oil port 9 through the pilot valve core 301 to assist in the unloading of the main oil circuit. When the second chamber needs to be depressurized, the pilot valve core 301 drives the valve body core 13 to change position, connecting the first oil port 1 and the second oil port 9 through the pilot valve core 301, increasing the oil unloading circuit of the second oil port 9, and efficiently and stably maintaining the pressure of the main oil circuit.

[0045] In summary, the explosion-proof valve provided in this embodiment completes the oil return operation through the second oil port 9 connected to the main oil circuit. The second oil port 9 is normally connected to the cone valve 8. When the main oil circuit is in the pressure-building working position, the second chamber of the cone valve 8 is pressurized, pushing the cone valve 8 close to the valve body 15 mounting seat 102 to cut off the oil circuit connecting the first oil port 1 and the second oil port 9. When the main oil circuit needs to retract the actuator, the pilot valve core 301 changes position, connecting the first oil port 1 and the second oil port 9 through the connecting oil circuit inside the pilot valve core 301. The oil flows between the connecting oil circuit of the first oil port 1 and the second oil port 9, the second chamber is depressurized, and the cone valve 8 is driven away from the mounting seat 102 to the second working position. At the same time, the connecting oil circuit of the first oil port 1 and the second oil port 9 through the mounting seat 102 is connected, and the oil is discharged through multiple circuits, thereby efficiently and stably completing the unloading operation and ensuring the safety of personnel and equipment.

[0046] In some embodiments, the valve body 15 has a valve cavity, and the valve cavity has a valve body core 13. The pilot valve core 301 is located at the bottom of the valve body core 13. The valve body core 13 and the pilot valve core 301 pass through the first oil port 1 and the second oil port 9, and are sealed with the valve cavity through the first valve sleeve 5 and the second valve sleeve 10, respectively, so as to drive the valve body core 13 to move through the pilot valve core 301, thereby realizing indirect control of the main oil circuit under high pressure. It is understandable that by placing both the pilot valve core 301 and the valve body core 13 within the valve cavity, and using the first valve sleeve 5 and the second valve sleeve 10 to form a double seal between the pilot valve core 301 and the valve body core 13, which pass through the first oil port 1 and the second oil port 9, the pilot valve core 301 drives the valve body core 13 to indirectly control the main oil circuit under high-pressure conditions. This design avoids the structural complexity and safety risks caused by directly driving high-pressure components, ensures no leakage of high-pressure media through the sealing design, and optimizes the power transmission path through the through-type layout. Ultimately, it achieves stable and precise control of the main oil circuit under high-pressure conditions, improving the reliability of system operation. More specifically, the valve body core 13 and the pilot valve core 301 can be selectively designed as an integral unit or a modular unit according to different operating conditions, adapting to maintenance schemes for dynamic changes in media pressure.

[0047] In some embodiments, the area of ​​the second chamber is larger than the area of ​​the first chamber. (Combined) Figure 1It can be understood that the first chamber of the cone valve 8 is the upper transverse oil passage 801, and the second chamber is the lower spring cavity 7. Under normal circumstances, the oil enters from the second oil port 9, passes through the transverse oil passage 801, and flows through the pilot valve core 301 into the spring cavity 7. The area of ​​the spring cavity 7 is larger than the area of ​​the transverse oil passage 801. When the oil flows into the cone valve 8, the pressure in the spring cavity 7 continuously increases, creating a pressure difference with the transverse oil passage 801. The oil overcomes the elastic force inside the spring cavity 7 and pushes the cone valve 8 to the first working position that contacts the mounting base 102, thereby cutting off the connection between the first oil port 1 and the second oil port 9, and thus stably maintaining the pressure-building working position of the main oil passage.

[0048] In some embodiments, the valve body 15 is connected to an overflow valve 16, which connects the cone valve 8 to the oil tank. Figure 2 It can be understood that the first oil port 1 is port A, the second oil port 9 is port B, the unloading port 2 is port DR, and port PL is the pilot oil port 3. When the oil circuit between the first oil port 1 and the second oil port 9 is not connected, the oil converges at the cone valve 8. When the pressure at the damping orifice of the cone valve 8 exceeds the preset threshold, the overflow valve 16 opens, and the oil flows through the overflow valve 16 to the unloading port 2 and back to the oil tank.

[0049] In some embodiments, the valve body 15 is provided with an oil discharge port 2 on its side, and the spring chamber of the valve core 13 and the overflow valve 16 are both connected to the oil discharge port 2. It can be understood that when the pilot oil port 3 is in the oil supply state, the first oil port 1 and the second oil port 9 can both form a return oil circuit to assist the main oil circuit for unloading; when the pipeline bursts, the explosion-proof valve is instantly cut off from the oil circuit and stops operating. Because the second oil port 9 is connected to the overflow valve 16 and connected to the return oil route of the oil tank, the valve body 15 can still maintain the pressure of the pipeline upstream of the burst point, allowing the equipment to be slowly recovered and ensuring emergency operation.

[0050] In some embodiments, the valve body core 13, the pilot valve core 301, and the cone valve 8 are connected to the valve body 15 via a first sealing element 14, a second sealing element 401, and a third sealing element 6, respectively. It can be understood that by connecting the valve body core 13, the pilot valve core 301, and the cone valve 8 to the valve body 15 via the first sealing element 14, the second sealing element 401, and the third sealing element 6, multiple independent sealing interfaces are formed. This effectively prevents leakage of high-pressure media at the connection points between each component and the valve body 15. Simultaneously, the separate sealing layout ensures that the functions of the valve body core 13, the pilot valve core 301, and the cone valve 8 do not interfere with each other. Even if one sealing element malfunctions, the others can still maintain a basic sealing effect, significantly improving the overall pressure resistance and operational safety of the system, and providing reliable sealing protection for the complex fluid control within the valve body 15.

[0051] Example 2:

[0052] This embodiment also provides a control method for an explosion-proof valve, which can be implemented by the explosion-proof valve in Embodiment 1, and specifically includes the following steps:

[0053] The position of the pilot valve core 301 is switched according to the oil supply status of the pilot port 3, so as to selectively connect the second chamber of the cone valve 8 to the first port 1 for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber, and causing the cone valve 8 to move.

[0054] When the cone valve 8 is controlled to be in the first working position, the oil circuit is connected to the second chamber of the cone valve 8 through the second oil port 9, so that the second chamber is pressurized; using the pressure difference between the first chamber and the second chamber, the cone valve 8 is driven to move to the first working position to cut off the connection between the first oil port 1 and the second oil port 9, so that the main oil circuit is in the pressure building working position.

[0055] When the cone valve 8 is controlled to be in the second working position, the second chamber of the cone valve 8 is connected to the first oil port 1 by the reversing of the pilot valve core 301, so that the second chamber is depressurized; by using the pressure difference between the first chamber and the second chamber, the cone valve 8 is driven to move to the second working position to connect the oil passage of the first oil port 1 and the second oil port 9 through the mounting base 102, so that the main oil passage is in an unloaded state.

[0056] At the same time, when the cone valve 8 is in the second working position, the pilot valve core 301 connects the first oil port 1 and the second oil port 9 through the oil passage of the pilot valve core 301 to assist the unloading work of the main oil passage.

[0057] By controlling multiple return oil circuits in a coordinated manner, and using the pressure difference between the first and second chambers as the core power to drive the cone valve 8 to switch positions, the system achieves automatic and reliable switching between pressure building and unloading states. When pressure building is required, the system can automatically cut off the drain oil circuit between the first port 1 and the second port 9 to ensure rapid pressure building in the main oil circuit. When unloading is required, the system uses the pressure difference to drive the cone valve 8 to connect the main drain oil circuit between the first port 1 and the second port 9 through the mounting base 102. At the same time, it also simultaneously opens the oil circuit between the first port 1 and the second port 9 through the pilot valve core 301. A large amount of oil passes through the first chamber of the cone valve 8, through the pilot valve core 301, and directly to the drain oil circuit connected to the first port 1, forming a dual unloading channel. This greatly improves the unloading efficiency and speed, effectively avoids power loss and system heat generation, and enhances the working efficiency and reliability of the entire hydraulic system.

[0058] In some embodiments, when the cone valve 8 is in the second operating position and the pilot port 3 is not supplying oil to the pilot valve core 301, if the pressure in the second chamber exceeds a preset pressure value, the oil flows back to the oil tank via the relief valve 16. It can be understood that when the system detects that the cone valve 8 is in the second operating position and the pilot port 3 is not supplying oil to the pilot valve core 301, if the pressure in the second chamber exceeds a preset safety value, the oil can be drained back to the oil tank via the relief valve 16, thereby preventing component damage or system failure due to continuous pressure increases, effectively ensuring the safety and reliability of the hydraulic system.

[0059] Working principle: The valve body 15 is fixed to the actuator cylinder by screws, with an O-ring seal between them to prevent oil leakage. The piston 4, valve core 13, first valve sleeve 5, second valve sleeve 10, spring seat 11, and valve core spring 12 are sequentially installed and placed inside the valve core 13 hole. Initially, under the action of the spring force, the bottom of the piston 4 is always in contact with the second seal 401 at the bottom of the valve body 15. After the valve core 13 reverses direction, the top of the valve body 15 contacts the first seal 14. The third seal 6, spring cavity 7, and cone valve 8 are sequentially installed inside the cone valve 8 cavity of the valve body 15. The cone valve 8 contacts the mounting seat 102 of the valve body 15 and is used to open or close the oil circuit. Simultaneously, the O-ring is fitted onto the third seal 6 and installed together at the threaded hole of the explosion-proof valve block for sealing. The oil discharge port 2 is always connected back to the oil tank.

[0060] When the PL port is not connected to the control oil, such as Figure 2 As shown, the pilot valve core 301 is located at the lowest end of the valve core 13 hole in the valve body. The oil passages at ports A and B are cut off by the upper step of the pilot valve core 301, and the oil passages are blocked. The main system oil passage passes through port B, through the damping hole of the cone valve 8, through the transverse oil passage 801 of the cone valve 8 chamber, and through the first valve sleeve 5 to the spring chamber 7 of the cone valve 8. Since the oil is cut off by the pilot valve core 301, the oil passing through the damping hole and the oil passing through the first valve sleeve 5 does not flow. At the same time, the area of ​​the spring chamber 7 of the cone valve 8 is larger than the area of ​​the transverse oil passage 801. Under the action of the spring force, the cone valve 8 is always in contact with the mounting seat 102 of the valve body 15, and the main system oil cannot be unloaded. At this time, the action of the actuator cannot be retracted, and the system is in the pressure building position. Only when the pressure value exceeds the set pressure value of the relief valve 16 will the relief valve 16 open, and the oil will return to the oil tank through the oil discharge port 2 via the relief valve 16.

[0061] When the control oil is supplied to the PL port, such as Figure 4As shown, the pilot valve core 301 moves upward within the valve chamber, connecting the oil passages at ports A and B. The main system oil passage passes through port B, via the transverse oil passage of the cone valve 8, and reaches the pilot valve core 301. Since the pilot valve core 301 is open, the oil can continue to reach port A. Simultaneously, the main system oil passage passes through port B, via the internal damping orifice of the cone valve 8, and reaches the spring chamber 7, continuing through the internal oil passage of the pilot valve core 301 before reaching port A. Because the oil is in a flowing state, when the pressure difference across the damping orifice of the cone valve 8 exceeds the force of the spring chamber 7, the cone valve 8 opens and moves downward, connecting ports A and B. At this time, the main system oil passage is in an unloaded state, and the actuator can retract.

[0062] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0063] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An explosion-proof valve, characterized in that, It includes a second oil port (9) connected to the main oil circuit, a first oil port (1) connected to the oil tank, a cone valve (8) and a pilot valve core (301). The cone valve (8) has a first chamber and a second chamber, and the first chamber is connected to the main oil circuit. The pilot valve core (301) switches positions according to the oil supply status of the pilot oil port (3) to selectively connect the second chamber of the cone valve (8) to the first oil port (1) for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber and causing the cone valve (8) to move. When the second chamber is pressurized, the cone valve (8) is in the first working position, and the cone valve (8) is in contact with the mounting seat (102) of the valve body (15), cutting off the connection between the first oil port (1) and the second oil port (9), and the main oil circuit is in the pressure building working position; when the second chamber is depressurized, the cone valve (8) is in the second working position, and the cone valve (8) is away from the mounting seat (102), connecting the oil circuit of the first oil port (1) and the second oil port (9) through the mounting seat (102), and the main oil circuit is switched to the unloading state; When the second chamber is depressurized, the pilot valve core (301) also connects the first oil port (1) and the second oil port (9) through the oil passage of the pilot valve core (301) to assist the unloading of the main oil passage.

2. The explosion-proof valve according to claim 1, characterized in that: The valve body (15) is provided with a valve cavity, and the valve body core (13) is provided in the valve cavity. The pilot valve core (301) is at the bottom of the valve body core (13). The valve body core (13) and the pilot valve core (301) pass through the first oil port (1) and the second oil port (9), and are sealed with the valve cavity through the first valve sleeve (5) and the second valve sleeve (10), respectively, so as to drive the valve body core (13) to move through the pilot valve core (301) to achieve indirect control of the main oil circuit under high pressure.

3. The explosion-proof valve according to claim 1, characterized in that: The area of ​​the second chamber is larger than the area of ​​the first chamber.

4. The explosion-proof valve according to claim 1, characterized in that: The valve body (15) is connected to an overflow valve (16), which is connected between the cone valve (8) and the oil tank.

5. The explosion-proof valve according to claim 4, characterized in that: The valve body (15) has an oil discharge port (2) on its side. The spring chamber of the valve core (13) and the overflow valve (16) are both connected to the oil discharge port (2).

6. The explosion-proof valve according to claim 2, characterized in that: The valve body core (13), the pilot valve core (301), and the cone valve (8) are respectively connected to the valve body (15) through the first sealing element (14), the second sealing element (401), and the third sealing element (6).

7. A control method for an explosion-proof valve according to any one of claims 1-6, characterized in that, The method includes the following steps: The position of the pilot valve core (301) is switched according to the oil supply status of the pilot port (3) to selectively connect the second chamber of the cone valve (8) to the first port (1) for pressure relief, thereby controlling the pressure difference between the second chamber and the first chamber and causing the cone valve (8) to move. When the cone valve (8) is controlled to be in the first working position, the oil circuit is connected to the second chamber of the cone valve (8) through the second oil port (9) to pressurize the second chamber; using the pressure difference between the first chamber and the second chamber, the cone valve (8) is driven to move to the first working position to cut off the connection between the first oil port (1) and the second oil port (9) so that the main oil circuit is in the pressure building working position; When the cone valve (8) is controlled to be in the second working position, the second chamber of the cone valve (8) is connected to the first oil port (1) by the reversal of the pilot valve core (301), so that the second chamber is depressurized; by using the pressure difference between the first chamber and the second chamber, the cone valve (8) is driven to move to the second working position to connect the oil passage of the first oil port (1) and the second oil port (9) through the mounting seat (102), so that the main oil passage is in an unloaded state; At the same time, when the cone valve (8) is in the second working position, the pilot valve core (301) connects the first oil port (1) and the second oil port (9) through the oil passage of the pilot valve core (301) to assist the unloading work of the main oil passage.

8. The control method for the explosion-proof valve according to claim 7, characterized in that, When the cone valve (8) is in the first working position and the pilot port (3) does not supply oil to the pilot valve core (301), when the pressure value in the second chamber exceeds the preset pressure value, the oil flows back to the oil tank through the overflow valve (16).

Images