Stop unloading valve group

Abstract

The invention provides a cut-off unloading valve bank which comprises a valve body, a cut-off valve, an unloading valve and a pilot valve element assembly, a main liquid inlet and a main liquid outlet are formed in the valve body, the main liquid inlet is connected with a liquid source, the main liquid outlet is connected with a load, and the pilot valve element assembly has a first working state and a second working state. The pilot valve core assembly comprises a first pilot valve and a second pilot valve, when the pilot valve core assembly is in a first working state, the stop valve is communicated with the liquid return box through the first pilot valve, and the unloading valve is communicated with the liquid source through the second pilot valve; and when the pilot valve element assembly is in the second working state, the stop valve is stopped from the liquid source through the first pilot valve, and the unloading valve is connected with a liquid return box through the second pilot valve. The stop valve and the liquid source are controlled to be stopped by controlling the pilot valve element assembly, and the unloading valve is communicated with the liquid return box, so that the stop unloading function is achieved, and the safety of the system is maintained.

Description

Technical Field

[0001] The present disclosure relates to the technical field of valves, and in particular to a stop unloading valve group. Background Art

[0002] The liquid source for coal mine mining generally uses a high-pressure large-flow emulsion pump station system to supply liquid to the loads (such as hydraulic supports) at the working face. The high-pressure liquid of the emulsion pump station system reaches the loads at the working face through rubber hoses. Since the conditions in the coal mine underground are relatively harsh, the pressure at the working face load is prone to sudden changes, resulting in phenomena such as pipe bursting or working face failures. At this time, it is necessary for the emulsion pump station system to stop supplying liquid to the working face, and at the same time unload the high-pressure liquid in the accumulator station, pipeline, and actuator. Currently, the most commonly used method is to stop the pump and unload, but the time required to cut off the power and stop the pump is relatively long, and the safety is not high enough. At the same time, the method of stopping the pump can only achieve the cut-off of high-pressure liquid and cannot achieve the rapid unloading of high-pressure liquid at the working face. Under the conditions of high pressure and large flow, a large operating torque is required, resulting in problems such as inconvenient operation, low safety, and untimely response. Summary of the Invention

[0003] The present disclosure aims to at least solve the technical problems in the prior art of stop unloading, such as the need for a large operating torque, inconvenient operation, low safety, and untimely response.

[0004] To this end, an object of the present disclosure is to provide a stop unloading valve group, which includes a valve body, a stop valve, an unloading valve, and a pilot valve core assembly. A total liquid inlet and a total liquid outlet are provided on the valve body. The total liquid inlet is connected to a liquid source, and the total liquid outlet is connected to a load. The pilot valve core assembly has a first working state and a second working state. The pilot valve core assembly includes a first pilot valve and a second pilot valve. When the pilot valve core assembly is in the first working state, the stop valve is communicated with a liquid return tank through the first pilot valve, and the unloading valve is communicated with the liquid source through the second pilot valve. When the pilot valve core assembly is in the second working state, the stop valve is cut off from the liquid source through the first pilot valve, and the unloading valve is communicated with the liquid return tank through the second pilot valve.

[0005] In some embodiments, the stop valve has a first liquid inlet and a first liquid outlet. The first liquid inlet is connected to the liquid source, and the first liquid outlet is connected to the load. When controlling the pilot valve core assembly to switch to the first working state, the first liquid inlet and the first liquid outlet are communicated. When controlling the pilot valve core assembly to switch to the second working state, the first liquid inlet and the first liquid outlet are cut off.

[0006] In some embodiments, the unloading valve has a second liquid inlet and a second liquid outlet. The second liquid inlet is connected to the load, and the second liquid outlet is connected to the liquid return tank. When the pilot valve core assembly is controlled to switch to the first working state, the second liquid inlet and the second liquid outlet are cut off. When the pilot valve core assembly is controlled to switch to the second working state, the second liquid inlet and the second liquid outlet are communicated with each other.

[0007] In some embodiments, the stop valve has a first control port. The first pilot valve has a third liquid inlet, a third liquid outlet, and a first working port. The third liquid inlet is connected to the liquid source, the third liquid outlet is connected to the liquid return tank, and the first working port is communicated with the first control port. When the first pilot valve is in the first working state, the third liquid outlet and the first working port are communicated with each other. When the first pilot valve is in the second working state, the third liquid inlet and the first working port are communicated with each other.

[0008] In some embodiments, the unloading valve has a second control port. The second pilot valve has a fourth liquid inlet, a fourth liquid outlet, and a second working port. The fourth liquid inlet is connected to the liquid source, the fourth liquid outlet is connected to the liquid return tank, and the second working port is communicated with the second control port. When the second pilot valve is in the first working state, the fourth liquid inlet and the second working port are communicated with each other. When the second pilot valve is in the second working state, the fourth liquid outlet and the second working port are communicated with each other.

[0009] In some embodiments, the stop valve includes a first end cover, a first valve sleeve, a first valve core, and a first elastic member. One end of the first end cover is installed on the outer side of the valve body. The first valve sleeve is installed in the valve body. The first valve core is movably arranged in the first valve sleeve. The first elastic member is installed between the first valve core and the first end cover. A first control cavity is formed between the first valve core and the first end cover, and the first control cavity is communicated with the first control port of the stop valve.

[0010] In some embodiments, the unloading valve includes a second end cover, a second valve sleeve, a second valve core, and a second elastic member. One end of the second end cover is installed on the outer side of the valve body. The second valve sleeve is installed in the valve body. The second valve core is movably arranged in the second valve sleeve. The second elastic member is installed between the second valve core and the second end cover. A second control cavity is formed between the second valve core and the second end cover, and the second control cavity is communicated with the second control port of the unloading valve.

[0011] In some embodiments, the diameter of one end of the first valve core close to the first liquid outlet is smaller than that of the end far from the first liquid outlet, and the diameter of one end of the second valve core close to the second liquid outlet is smaller than that of the end far from the second liquid outlet.

[0012] In some embodiments, a first valve cavity and a second valve cavity are formed in the valve body. The shut-off valve is arranged in the first valve cavity, and the unloading valve is arranged in the second valve cavity. The total liquid inlet and the total liquid outlet are communicated through the first valve cavity, and the first valve cavity and the second valve cavity are communicated through a flow channel.

[0013] In some embodiments, the pilot valve core assembly is connected to a controller, and the controller is configured to switch the pilot valve core assembly from the first working state to the second working state when the pressure change range of the load reaches a preset value.

[0014] The shut-off unloading valve group provided by the embodiments of the present disclosure has the following beneficial effects: when a fault occurs on the working surface, by controlling the pilot valve core assembly to switch to the second working state, the shut-off valve is controlled to cut off the liquid source, and the unloading valve is connected to the return liquid tank to achieve the shut-off unloading function and maintain the safety of the system. Under the working conditions of low pressure and small flow and high pressure and large flow, remote control can be realized, with convenient operation, fast response speed and high safety factor, which is conducive to the unmanned and intelligent mining of coal mines;

[0015] In the first working state, the shut-off valve is communicated with the return liquid tank through the first pilot valve, and the unloading valve is communicated with the liquid source through the second pilot valve. The unloading valve is communicated with the liquid source through the second pilot valve to ensure that the unloading valve is in a normally closed state, avoiding the influence of the hydraulic system pressure caused by the accidental opening of the unloading valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 is the schematic diagram of the shut-off unloading valve group in the embodiments of the present disclosure;

[0018] Figure 2 is the structural diagram of the shut-off unloading valve group in the embodiments of the present disclosure;

[0019] Figure 3 is the cross-sectional view of the shut-off unloading valve group in the embodiments of the present disclosure;

[0020] Figure 4 is a schematic structural diagram of the globe valve in the embodiments of the present disclosure;

[0021] Figure 5 is a schematic structural diagram of the unloading valve in the embodiments of the present disclosure.

[0022] Reference numerals:

[0023] 1, valve body; 11, total liquid inlet; 12, total liquid outlet; 13, first valve cavity; 14, second valve cavity; 15, flow channel; 2, globe valve; 21, first liquid inlet; 22, first liquid outlet; 23, first end cover; 24, first valve sleeve; 25, first valve core; 26, first elastic member; 27, first control cavity; 29, first sealing portion; 210, second sealing portion; 3, unloading valve; 31, second liquid inlet; 32, second liquid outlet; 33, second end cover; 34, second valve sleeve; 35, second valve core; 36, second elastic member; 37, second control cavity; 4, pilot valve core assembly; 41, first pilot valve; 411, third liquid inlet; 412, third liquid outlet; 413, first working port; 42, second pilot valve; 421, fourth liquid inlet; 422, fourth liquid outlet; 423, second working port; 43, check valve; 5, liquid source; 6, load; 7, liquid return tank. Detailed embodiments

[0024] Reference is made herein to the various aspects and features of the present disclosure with reference to the accompanying drawings.

[0025] It should be understood that various modifications can be made to the embodiments claimed herein. Accordingly, the above description should not be construed as limiting, but merely as exemplary of the embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.

[0026] The accompanying drawings, which are included in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0027] These and other features of the present disclosure will become apparent from the following description of the preferred forms of the embodiments, given by way of non - limiting example with reference to the accompanying drawings.

[0028] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present disclosure, which have the features as claimed and thus are all within the protection scope defined hereby.

[0029] When considered in conjunction with the accompanying drawings, the above and other aspects, features, and advantages of the present disclosure will become more apparent in view of the following detailed description.

[0030] Specific embodiments of the present disclosure will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but are merely used as a basis for the claims and a representative basis for teaching those skilled in the art to use the present disclosure in substantially any suitable detailed structure in a variety of ways.

[0031] The first embodiment of the present disclosure provides a cut-off unloading valve group, as Figures 1 - 5 shown. The cut-off unloading valve group includes a valve body 1, a cut-off valve 2, an unloading valve 3, and a pilot spool assembly 4. Among them, a first valve cavity 13 and a second valve cavity 14 are provided in the valve body 1. At least a part of the cut-off valve 2 is installed in the first valve cavity 13, and at least a part of the unloading valve 3 is installed in the second valve cavity 14. A total liquid inlet 11, a total liquid outlet 12, and a total liquid return port ( Figure 2 marked at position R) are provided on the side of the valve body 1. The total liquid inlet 11 is communicated with a liquid source 5, the total liquid outlet 12 is communicated with a load 6, and the total liquid return port is communicated with a liquid return tank. In this embodiment, the liquid source 5 refers to an emulsion pump station (the total liquid inlet 11 is connected to the outlet of the emulsion pump station), and the load 6 refers to a hydraulic support on the working face. Of course, the working face may also include other actuators and accumulators, etc. The pilot spool assembly 4 has multiple working states, specifically including a first working state and a second working state. Controlling the pilot spool assembly 4 to switch between the first working state and the second working state can make the cut-off valve 2 communicate with or cut off the liquid source 5. At the same time, by controlling the pilot spool assembly 4 to switch between the first working state and the second working state, the unloading valve 3 can also be made to communicate with or cut off the liquid return tank 7. Here, the first working state means that the liquid source 5 supplies liquid to the load 6 under normal working conditions, and the second working state means that a fault occurs in the load 6 on the working face, and cut-off unloading is performed. In practical applications, for a fully mechanized coal mining working face, during normal operation, the emulsion pump station pumps the liquid to the cut-off valve 2 and then enters each hydraulic support through the pipeline, that is: the cut-off valve 2 communicates with the emulsion pump station, and the unloading valve 3 cuts off from the hydraulic support; when a fault occurs (such as a sudden change in pressure), it is usually necessary to control the cut-off valve 2 to cut off the emulsion pump station to prevent the liquid from continuing to supply to the working face, and at the same time, it is also necessary to control the unloading valve 3 to communicate with the liquid return tank 7 to unload each hydraulic support. In this solution, by controlling the pilot spool assembly 4 to switch between different working states, the cut-off valve 2 and the unloading valve 3 are controlled to switch between different working states to achieve the cut-off unloading function and maintain the safety of the system. Under the working conditions of low pressure and small flow rate and high pressure and large flow rate, remote control can be achieved, with convenient operation, fast response speed, and high safety factor, which is conducive to realizing unmanned and intelligent mining of coal mines.

[0032] In addition, the pilot spool assembly 4 is connected to a controller, and the controller is configured to switch the pilot spool assembly 4 from the first working state to the second working state when the pressure change amplitude of the load 6 reaches a preset value. Specifically, the pressure detection device feeds back the detected pressure value at the load 6 to the controller, and the controller analyzes the pressure detection value to determine the change amplitude of the pressure within a rated time. If the change amplitude exceeds the preset value, it indicates that the pressure at the load 6 is abnormal, and the controller controls the pilot spool assembly 4 to switch from the first working state to the second working state to achieve cutoff and unloading.

[0033] Among them, the pilot spool assembly 4 includes a first pilot valve 41 and a second pilot valve 42. When controlling the pilot spool assembly 4 to switch to the first working state, the shut-off valve 2 is connected to the return liquid tank 7 through the first pilot valve 41, and the unloading valve 3 is connected to the liquid source 5 through the second pilot valve 42. When controlling the pilot spool assembly 4 to switch to the second working state, the shut-off valve 2 cuts off the liquid source 5 and the load 6 through the first pilot valve 41, and the unloading valve 3 is communicated with the return liquid tank 7 through the second pilot valve 42 to achieve unloading. Here, when the liquid source 5 and the load 6 are working normally, the unloading valve 3 is communicated with the liquid source 5 through the second pilot valve 42, and the second spool 35 of the unloading valve 3 can be tightly pressed against the second valve sleeve 34 of the unloading valve 3 to ensure that the unloading valve 3 is in the normally closed first working state, avoiding misoperation and opening of the second spool 35 of the unloading valve 3, thereby having an adverse impact on the pressure of the emulsion pump station system.

[0034] Specifically, as Figure 1 shown, the overflow spool assembly has a first liquid inlet 21, a first liquid outlet 22, and a first control port (not shown in the figure). The first liquid inlet 21 is connected to the liquid source 5, and the second liquid inlet 31 is connected to the load 6; the unloading valve 3 has a second liquid inlet 31, a second liquid outlet 32, and a second control port (not shown in the figure). The second liquid inlet 31 is connected to the load 6, and the second liquid outlet 32 is connected to the return liquid tank 7; the pilot spool assembly 4 includes a first pilot valve 41 and a second pilot valve 42. The first pilot valve 41 has a third liquid inlet 411, a third liquid outlet 412, and a first working port 413. The third liquid inlet 411 is connected to the liquid source 5, the third liquid outlet 412 is connected to the return liquid tank 7, and the first working port 413 is communicated with the first control port. The second pilot valve 42 has a fourth liquid inlet 421, a fourth liquid outlet 422, and a second working port 423. The fourth liquid inlet 421 is connected to the liquid source 5, the fourth liquid outlet 422 is connected to the return liquid tank 7, and the second working port 423 is communicated with the second control port.

[0035] Among them, the first pilot valve 41 and the second pilot valve 42 can be switched between the first working state and the second working state by electromagnetic control, for example, controlled by an electromagnet. During normal operation, the first pilot valve 41 and the second pilot valve 42 are in a power-off state. At this time, the first pilot valve 41 and the second pilot valve 42 are in the first working state. In the first pilot valve 41, the third liquid outlet 412 is communicated with the first working port 413, the third liquid inlet 411 is cut off from the third liquid outlet 412, and the third liquid inlet 411 is cut off from the first working port 413; in the shut-off valve 2, the first liquid inlet 21 is communicated with the second liquid inlet 31; at the same time, in the unloading valve 3, the second liquid inlet 31 is cut off from the second liquid outlet 32. At this time, the shut-off valve 2 is in an open state, and the unloading valve 3 is in a closed state. The liquid provided by the liquid source 5 sequentially enters the load 6 at the working surface along the first liquid inlet 21 and the first liquid outlet 22. Here, when the first pilot valve 41 and the second pilot valve 42 are powered off during normal operation, it can achieve the effect of energy saving and at the same time improve the service life of the pilot valve core assembly 4.

[0036] When a fault occurs at the working surface, the first pilot valve 41 and the second pilot valve 42 are in a powered-on state. At this time, the first pilot valve 41 and the second pilot valve 42 are in the second working state. In the first pilot valve 41, the third liquid inlet 411 is communicated with the first working port 413, the third liquid inlet 411 is cut off from the third liquid outlet 412, and the third liquid outlet 412 is cut off from the first working port 413. In the shut-off valve 2, the first liquid inlet 21 is cut off from the second liquid inlet 31. In the unloading valve 3, the second liquid inlet 31 is communicated with the second liquid outlet 32. At this time, the shut-off valve 2 is in a cut-off state, cutting off the passage between the liquid source 5 and the working surface load 6, and there is no longer liquid supply to the working surface. The unloading valve 3 is in a communicated state to relieve the pressure of the working surface.

[0037] Among them, the fourth liquid outlet 422 and the return liquid tank 7 are connected through a check valve 43. When the cut-off unloading is achieved, the pressure of the liquid flowing back to the return liquid tank 7 may be relatively high. The check valve 43 is provided so that the liquid can only flow unidirectionally from the fourth liquid outlet 422 along the return liquid tank 7, preventing the liquid from flowing reversely and opening the second pilot valve 42, resulting in unloading failure.

[0038] Further, as Figure 2 and Figure 3As shown, the total liquid inlet 11 and the total liquid outlet 12 are communicated through the first valve chamber 13, and the first valve chamber 13 and the second valve chamber 14 are communicated through a flow channel 15. The stop valve 2 is used to control the communication and cut-off between the total liquid inlet 11 and the total liquid outlet 12. The flow channel 15 is communicated with the liquid return tank 7 through a pressure relief valve 3, and the pressure relief valve 3 is used to control the communication and cut-off between the flow channel 15 and the liquid return tank 7. Here, the flow channel 15 and the total liquid outlet 12 are arranged on the same straight line along the first direction (such as the length direction) of the valve body 1, which is convenient for processing and reduces the processing procedures. The flow channel 15 and the first valve chamber 13 are arranged on the same straight line along the second direction (such as the height direction) of the valve body 1. When the liquid enters the stop valve 2 through the flow channel 15, the flowing path is shorter, making the response speed of this liquid return valve faster.

[0039] Further, the stop valve 2 includes a first end cover 23, a first valve sleeve 24, a first valve core 25 and a first elastic member 26. The first end cover 23 is installed on the outer side of the valve body 1, the first valve sleeve 24 is installed in the valve body 1, the first valve core 25 is movably arranged in the first valve sleeve 24, and the first elastic member 26 is installed between the end of the first valve core 25 close to the first end cover 23 and the first end cover 23. A first control chamber 27 is formed between the first valve core 25 and the first end cover 23, and the first control chamber 27 is communicated with the first control port of the overflow valve core assembly. The first liquid inlet 21 is arranged at the end of the first valve sleeve 24 away from the first end cover 23, and the first liquid outlet 22 is arranged on the outer periphery of the first valve sleeve 24. By controlling the first pilot valve 41 of the pilot valve core assembly 4 to adjust the pressure in the first control chamber 27, the first liquid inlet 21 and the first liquid outlet 22 are communicated or cut off. During normal operation, the liquid flowing into the stop and pressure relief valve group from the total liquid inlet 11 applies pressure to one end of the first valve core 25 away from the end cover. The first elastic member 26 is compressed, the pressure in the first control chamber 27 decreases, and the first valve core 25 moves towards the end close to the first end cover 23 to communicate the first liquid inlet 21 and the first liquid outlet 22. The liquid entering the valve body 1 from the total liquid inlet 11 flows to each load 6 on the working surface through the first liquid inlet 21, the first liquid outlet 22 and the total liquid outlet 12 in sequence. That is, during normal operation, the stop valve 2 is in an open state, and the liquid continuously flows in from the first liquid inlet 21 and flows out from the first liquid outlet 22. When a failure occurs at the load 6 end, since the first working port 413 is communicated with the first control chamber 27, the pressure in the first control chamber 27 increases, and the first valve core 25 moves in the direction away from the first end cover 23 until the first liquid inlet 21 and the first liquid outlet 22 are blocked.

[0040] The unloading valve 3 assembly includes a second end cap 33, a second valve sleeve 34, a second valve core 35, and a second elastic member 36. The second end cap 33 is installed on the outer side of the valve body 1. The second valve sleeve 34 is installed in the valve body 1. The second valve core 35 is movably arranged in the second valve sleeve 34. A second elastic member 36 is installed between the end of the second valve core 35 close to the second end cap 33 and the second end cap 33. A second control chamber 37 is formed between the second valve core 35 and the second end cap 33. The second control chamber 37 is communicated with the second control port of the unloading valve 3. The second liquid inlet 31 is arranged at the end of the second valve sleeve 34 away from the second end cap 33. The second liquid outlet 32 is arranged on the outer periphery of the second valve core 35. By controlling the second pilot valve 42 of the pilot valve core assembly 4, the pressure of the second control chamber 37 is adjusted to make the second liquid inlet 31 and the second liquid outlet 32 communicate or cut off. During normal operation, the liquid source 5 flows liquid into the second control chamber 37 through the second pilot valve 42. The pressure in the second control chamber 37 increases, causing the second valve core 35 to move towards the direction close to the second liquid inlet 31, blocking the second liquid inlet 31, and also blocking the passage between the second liquid inlet 31 and the liquid return tank 7. That is, during normal operation, the unloading valve 3 is in a normally closed state. When a fault occurs at the load 6 end, the liquid in the second control chamber 37 flows to the liquid return tank 7 through the fourth liquid outlet 422. The pressure in the second control chamber 37 decreases, and the second valve core 35 moves towards the direction away from the second liquid inlet 31 to communicate the second liquid inlet 31 and the second liquid outlet 32.

[0041] Wherein, the diameter of the end of the first valve core 25 close to the first liquid outlet 22 is smaller than the diameter of the end away from the first liquid outlet 22. Due to the different areas at both ends of the first valve core 25, there is a pressure difference between the pressures acting on both ends of the first valve core 25, which is beneficial to realizing the rapid opening and closing of the first valve core 25 and improving the response speed. Similarly to the above-mentioned first valve core 25, the diameter of the end of the second valve core 35 close to the second liquid outlet 32 is smaller than the diameter of the end away from the second liquid outlet 32.

[0042] When installing the globe valve 2, since the first end cover 23 is arranged outside the valve body 1 and the first end cover 23 is connected to the valve body 1 by fasteners, the globe valve 2 can be inserted through the first end cover 23, and the installation and disassembly of the globe valve 2 are convenient and fast. Similarly, when installing the unloading valve 3, since the second end cover 33 is arranged outside the valve body 1 and the second end cover 33 is connected to the valve body 1 by fasteners, the unloading valve 3 can be inserted through the second end cover 33. The globe valve 2 is inserted into the valve body 1 through the first end cover 23, and the unloading valve 3 is inserted into the valve body 1 through the second end cover 33. The installation and disassembly of the globe valve 2 and the unloading valve 3 are convenient and fast, which is convenient for maintenance. In addition, the first end cover 23 and the second end cover 33 are respectively arranged on both sides of the valve body 1, which can avoid interference between the first end cover 23 and the second end cover 33, and if the globe valve 2 and the unloading valve 3 are arranged in parallel, the distance between the globe valve 2 and the unloading valve 3 can be reduced, thereby reducing the volume of the entire globe unloading valve group.

[0043] In this embodiment, as Figure 4 and Figure 5 shown, the globe valve 2 and the unloading valve 3 have the same structure, and the parts have good versatility, which is convenient for installation and maintenance. Further, a first sealing portion 29 is provided at the end of the first valve core 25 close to the first liquid inlet 21, and a second sealing portion 210 is provided inside the first valve sleeve 24 and is matched with the first sealing portion 29. Here, the first sealing portion 29 is formed by machining a conical surface at the end of the first valve core 25. When the first valve core 25 approaches the second sealing portion 210, the second sealing portion 210 and the first sealing portion 29 are wedged with each other. By forming a hard seal between the first sealing portion 29 on the first valve core 25 and the second sealing portion 210 on the first valve sleeve 24, the number of parts can be reduced. On the premise of ensuring the flow rate of the globe valve 2, the diameter of the first valve sleeve 24 can be reduced, which is beneficial to reducing the volume of the entire globe unloading valve group. Since the structures of the globe valve 2 and the unloading valve 3 are the same, a third sealing portion is provided on the second valve core 35, and a fourth sealing portion is provided on the second valve sleeve 34 and is matched with the third sealing portion. The third sealing portion and the fourth sealing portion also form a hard seal, further reducing the diameter of the second valve sleeve 34, which is beneficial to further reducing the volume of the entire globe unloading valve group.

[0044] In this embodiment, at least one sealing ring is provided between the first valve core 25 and the first valve sleeve 24 and between the second valve core 35 and the second valve sleeve 34 to improve the sealing performance. The sealing ring can be an O-ring, a V-ring, a Y-ring or a U-ring, etc.

[0045] In addition, taking a fully mechanized coal mining face as an example, the cut-off unloading valve group can be used for a single first working face. That is, the pump station and the working face are connected through the cut-off unloading valve group. During normal operation, the pump station is connected to the first working face and supplies liquid to it. After a failure occurs in the first working face, the pump station is disconnected from the first working face, and the first working face realizes unloading. A set of pump stations can also supply liquid to multiple working faces at the same time. For example, during normal operation, the pump station supplies liquid to the second working face and the third working face at the same time. If a failure occurs in the second working face among them, the second working face and the pump station are disconnected through the unloading cut-off valve group, but the pump station does not need to stop operating, and the operation of the third working face is not affected. That is, when the cut-off unloading valve group is used in multiple working faces, when a certain working face fails or is under maintenance, it does not affect the operation of the pump station and the operation of other working faces, which is convenient for maintaining the faulty working face.

[0046] The second embodiment of the present disclosure provides a hydraulic system, including the above-mentioned cut-off unloading valve group.

[0047] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present disclosure.

[0048] In the description of the present disclosure, the "first feature" and "second feature" may include one or more of such features.

[0049] In the description of the present disclosure, the meaning of "a plurality" is two or more.

[0050] In the description of the present disclosure, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween.

[0051] In the description of the present disclosure, the first feature being "above", "above the top" and "on the upper surface" of the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher horizontal height than the second feature.

[0052] In the description of the present disclosure, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0053] Although the embodiments of the present disclosure have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present disclosure, and the scope of the present disclosure is defined by the claims and their equivalents.

Claims

1. A cut-off unloading valve group, characterized in that: It includes a valve body, a stop valve, a unloading valve and a pilot valve core assembly. The valve body is provided with a total liquid inlet and a total liquid outlet. The total liquid inlet is connected to a liquid source, and the total liquid outlet is connected to a load. The pilot valve core assembly has a first working state and a second working state. The pilot valve core assembly includes a first pilot valve and a second pilot valve. When the pilot valve core assembly is in the first working state, the stop valve is communicated with a liquid return tank through the first pilot valve, and the unloading valve is communicated with the liquid source through the second pilot valve; when the pilot valve core assembly is in the second working state, the stop valve is cut off from the liquid source through the first pilot valve, and the unloading valve is communicated with the liquid return tank through the second pilot valve.

2. The stop unloading valve assembly according to claim 1, characterized in that: The stop valve has a first liquid inlet and a first liquid outlet, the first liquid inlet is connected to the liquid source, and the first liquid outlet is connected to the load. When the pilot valve core assembly is controlled to switch to the first working state, the first liquid inlet and the first liquid outlet are connected. When the pilot valve core assembly is controlled to switch to the second working state, the first liquid inlet and the first liquid outlet are cut off.

3. The stop unloading valve assembly according to claim 1, characterized in that: The unloading valve has a second liquid inlet and a second liquid outlet, the second liquid inlet is connected to the load, and the second liquid outlet is connected to the return liquid tank. When the pilot valve core assembly is controlled to switch to the first working state, the second liquid inlet and the second liquid outlet are cut off, and when the pilot valve core assembly is controlled to switch to the second working state, the second liquid inlet and the second liquid outlet are connected.

4. The stop unloading valve assembly according to claim 2, characterized in that: The stop valve has a first control port, the first pilot valve has a third liquid inlet, a third liquid outlet and a first working port, the third liquid inlet is connected to the liquid source, the third liquid outlet is connected to the liquid return tank, the first working port is connected to the first control port, when the first pilot valve is in the first working state, the third liquid outlet is connected to the first working port, and when the first pilot valve is in the second working state, the third liquid inlet is connected to the first working port.

5. The stop unloading valve assembly according to claim 3, characterized in that: The unloading valve has a second control port, the second pilot valve has a fourth liquid inlet, a fourth liquid outlet and a second working port, the fourth liquid inlet is connected to the liquid source, the fourth liquid outlet is connected to the liquid return tank, the second working port is connected to the second control port, when the second pilot valve is in the first working state, the fourth liquid inlet is connected to the second working port, and when the second pilot valve is in the second working state, the fourth liquid outlet is connected to the second working port.

6. The stop unloading valve assembly according to claim 2, characterized in that: The stop valve includes a first end cover, a first valve sleeve, a first valve core and a first elastic member, one end of the first end cover is installed on the outside of the valve body, the first valve sleeve is installed in the valve body, the first valve core is movably arranged in the first valve sleeve, the first elastic member is installed between the first valve core and the first end cover, a first control chamber is formed between the first valve core and the first end cover, and the first control chamber is connected to the first control port of the stop valve.

7. The stop unloading valve assembly according to claim 6, characterized in that: The unloading valve includes a second end cover, a second valve sleeve, a second valve core and a second elastic member, one end of the second end cover is installed on the outside of the valve body, the second valve sleeve is installed in the valve body, the second valve core is movably arranged in the second valve sleeve, a second elastic member is installed between the second valve core and the second end cover, a second control chamber is formed between the second valve core and the second end cover, and the second control chamber is connected to the second control port of the unloading valve.

8. The stop unloading valve assembly according to claim 7, characterized in that: The diameter of one end of the first valve core close to the first liquid outlet is smaller than the diameter of the other end away from the first liquid outlet; and / or A diameter of an end of the second valve core close to the second liquid outlet is smaller than a diameter of an end of the second valve core far from the second liquid outlet.

9. The stop unloading valve assembly according to claim 1, characterized in that: The valve body is provided with a first valve cavity and a second valve cavity, the stop valve is arranged in the first valve cavity, the unloading valve is arranged in the second valve cavity, the total liquid inlet and the total liquid outlet are connected through the first valve cavity, and the first valve cavity and the second valve cavity are connected through a flow channel.

10. The stop unloading valve assembly according to claim 1, characterized in that: The pilot valve core assembly is connected to a controller, and the controller is configured to switch the pilot valve core assembly from the first working state to the second working state when the pressure variation amplitude of the load reaches a preset value.

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