Quick pressure relief type hydraulic control one-way valve

Abstract

The quick pressure relief type hydraulic control one-way valve comprises a valve body, a valve cavity is formed in the valve body, a valve rod is assembled in the valve cavity, the valve body is provided with a port PA, a port A and a port K, a main valve port is formed in the valve cavity, the valve rod is sleeved with a valve element assembly, the valve element assembly comprises a main valve element and an auxiliary valve element, and the valve rod is provided with a first matching face and a second matching face. When the second matching face is matched with the auxiliary valve element in an abutting and pushing mode, a gap is formed between the main valve element and the first matching face, a movable cavity is defined by the main valve element, the auxiliary valve element and the valve body, and an auxiliary valve port is formed between the auxiliary valve element and the main valve element. The valve body is provided with a sealing cavity which is communicated with the opening A, a communicating hole is connected between the sealing cavity and the movable cavity, the hole diameter of the communicating hole is smaller than the cavity diameter of the movable cavity and the sealing cavity, and a plugging piece is movably assembled in the sealing cavity and reciprocates under the acting force of the differential pressure of the movable cavity and the sealing cavity. And the defect of instantaneous pressure building of the rod cavity of the hydraulic cylinder caused by slow opening of the hydraulic control one-way valve is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic support pushing systems, and in particular to a rapid pressure relief type hydraulically controlled one-way valve. Background Art

[0002] With the development of comprehensive mining technology, efficient comprehensive mining technology has been widely promoted and applied in coal mines of all sizes. As one of the important comprehensive mining equipment, the reliability of hydraulic support is of vital importance. As one of the main functions of hydraulic support, the push hydraulic system is mainly composed of a reversing valve, a hydraulically controlled one-way valve, a safety valve, a push hydraulic cylinder, a return liquid circuit breaker valve and other pipeline accessories. The function of the hydraulically controlled one-way valve is mainly to lock the working medium of the rod chamber of the push hydraulic cylinder to ensure that the push rod will not extend under a certain pulling force when the associated adjacent frame is pulled. The hydraulically controlled one-way valve generally includes a valve body, a valve chamber is arranged in the valve body, and the valve body is provided with a PA port, an A port and a K port, wherein the PA port is connected to the rodless chamber of the hydraulic cylinder through the reversing valve, the A port is connected to the rod chamber of the hydraulic cylinder, and the K port is connected to the rodless chamber of the hydraulic cylinder. A valve core assembly is installed in the guide of the valve cavity. The valve core assembly includes a valve core mounted on a valve stem which is inserted into the valve cavity. A return spring is installed on one end of the valve stem, and the other end is connected to the K port. A main valve port is provided on the side wall of the valve cavity between the PA port and the A port. The corresponding valve core has a conical surface matching portion matching the main valve port, and the main valve port is arranged on the side facing the A port.

[0003] During the actual working process, when the hydraulic cylinder contracts to perform a pushing and sliding action, the outside of the hydraulic cylinder contracts under the load, the reversing valve connects the rodless chamber and the PA port, the PA port is pressurized, the liquid flows into the valve chamber through the PA port, and pushes open the seal between the valve core and the valve port, enters the A port, and flows into the rod chamber through the A port, realizing the contraction of the hydraulic cylinder.

[0004] When the hydraulic cylinder needs to be extended to perform the rack pulling action, the reversing valve works, the PA port is connected with the return liquid, the rodless chamber is connected with the liquid supply pipeline, the pressure in the rodless chamber increases, and the pressure of the K port connected with the rodless chamber increases, pushing the valve stem to compress the return spring and move it, and opening the valve port, the PA port and the A port are connected, the liquid flow in the rod chamber enters the valve chamber through the A port, and flows from the PA port into the return liquid pipeline, realizing the extension of the hydraulic cylinder.

[0005] There is also a safety valve between port A and the rod chamber. The function of the safety valve is to ensure that the hydraulic cylinder will release pressure in time when the pressure in the rod chamber is too high under any abnormal situation, so as to protect the hydraulic cylinder and other related hydraulic parts from damage. However, the safety valve itself has a certain service life. If it is opened frequently, the safety valve will be damaged quickly, affecting the safety of the push system and the coal mining efficiency, and increasing the system maintenance workload.

[0006] In the actual working conditions of the push system, the push hydraulic cylinder will not only cause the safety valve to open when it is occasionally subjected to an overload external force, but also the safety valve will often open during the operation of the shifting frame, especially when the hydraulic control one-way valve and the push hydraulic cylinder are connected in a plate-type manner, the safety valve will open more seriously. For example, at the moment when the hydraulic cylinder is extended, before the hydraulic cylinder is extended, the high-pressure liquid in all the hydraulic component cavities that communicate with each chamber in the hydraulic control one-way valve and the rod chamber of the hydraulic cylinder is locked by the valve core (such as the active chamber formed by the valve core assembly and the valve core, the spring assembly chamber, etc.). Therefore, when the K port needs to be pressurized to push the valve port, the reaction force generated by the locked high-pressure liquid is large, causing the valve core to be unable to open quickly. Since the hydraulic control one-way valve cannot be opened in time, the pressure in the rod chamber of the hydraulic cylinder will rise sharply to the opening pressure of the safety valve, causing the safety valve to open, affecting the service life of the safety valve, causing the safety valve to be damaged prematurely, and increasing the maintenance workload. In serious cases, it has a great impact on the coal mining efficiency. Summary of the invention

[0007] The purpose of the present invention is to provide a rapid pressure relief hydraulically controlled one-way valve to solve the problem that the hydraulically controlled one-way valve in the prior art cannot be opened quickly, causing the pressure in the rod chamber to increase sharply, and the safety valve is frequently opened, which affects the service life of the safety valve.

[0008] In order to solve the above problems, the rapid pressure relief hydraulically controlled one-way valve involved in the present invention adopts the following technical solutions: A quick pressure relief hydraulically controlled one-way valve comprises a valve body, a valve cavity extending forward and backward in the valve body, a valve stem is installed in the guide in the valve cavity, a PA port, an A port and a K port are arranged on the valve body, a main valve port is formed between the PA port and the A port in the valve cavity, and the rear end is communicated with the K port, a valve core assembly is sleeved on the valve stem, the rear end of the valve core assembly cooperates with the main valve port to isolate the PA port and the A port, a reset spring is installed on the front end top of the valve core assembly, the valve core assembly comprises a main valve core and an auxiliary valve core which are coaxially arranged and cooperate with front and rear limit stops, the main valve core is located at the rear side of the auxiliary valve core, the valve stem has a first mating surface which is pushed forward against the main valve core, and also has a first mating surface which is pushed forward against the auxiliary valve core. A second mating surface is push-fitted. When the second mating surface and the auxiliary valve core are push-fitted and move synchronously, there is a gap between the main valve core and the first mating surface. An active cavity connected with the PA port is formed between the main valve core, the auxiliary valve core and the valve body. An auxiliary valve port is arranged between the auxiliary valve core and the main valve core to separate the active cavity from the PA port. The valve body is also provided with a sealing cavity, which is connected with the A port. A connecting hole is connected between the sealing cavity and the active cavity. The aperture of the connecting hole is smaller than the cavity diameters of the active cavity and the sealing cavity. A sealing member is movably assembled in the sealing cavity. The sealing member is subjected to the pressure difference between the active cavity and the sealing cavity and reciprocates in the sealing cavity to block the connecting hole and open the connecting hole.

[0009] In a preferred embodiment, a plugging edge is provided at the front end of the valve stem in the valve cavity, the cavity between the plugging edge and the valve core assembly constitutes an active cavity, a sealed cavity is formed between the front side of the plugging edge and the valve body, and the communicating hole is provided on the plugging edge.

[0010] In a preferred embodiment, the sealing member is a movable baffle plate guided and assembled in the sealing cavity, the rear side plate surface of the movable baffle plate is adapted to fit with the front side wall of the blocking edge to form a sealing surface for sealing the flow hole, and the front side of the movable baffle plate has an extrusion cavity connected to the sealing cavity.

[0011] In a preferred embodiment, a through hole is provided on the blocking edge for the front end of the valve stem to pass through, and an anti-slip portion is provided on the rear side plate surface of the movable baffle at a coaxial position corresponding to the valve stem, and the anti-slip portion cooperates with the front end movable sleeve of the valve stem and the anti-slip limiter.

[0012] In a preferred embodiment, the front end of the valve stem has an external thread, and a connecting sleeve is provided on the rear side wall of the movable baffle. The inner hole of the connecting sleeve is formed with an internal thread section and a smooth sleeve section from back to front. After the valve stem is threadedly connected to the connecting sleeve, it is guided by the smooth sleeve section to slide and prevent it from falling off.

[0013] In a preferred embodiment, a connecting structure connecting the auxiliary valve port and the PA port is provided on the valve stem and / or the main valve core.

[0014] In a preferred embodiment, the communication structure is a flow groove provided on the outer side wall of the valve stem, and the flow groove extends along the front-to-back direction to connect the auxiliary valve port and the PA port.

[0015] In a preferred embodiment, the valve body includes a valve housing and a valve sleeve sealed in the valve housing, the valve sleeve has a PA hole connected to the PA port, an A hole connected to the A port, and a guide hole connected to the K port, the valve stem is installed in the guide hole, and the front end of the valve sleeve has a blocking edge formed by bending inward, and the blocking edge constitutes the blocking edge.

[0016] In a preferred embodiment, a side through hole connecting port A and the sealing cavity is further provided on the side wall of the valve sleeve.

[0017] In a preferred embodiment, the rear end of the inner side wall of the valve sleeve has an inner annular step cooperating with the valve stem guide, and an anti-whistle hole connecting the PA port and the guide hole is provided on the side wall of the valve sleeve behind the inner annular step.

[0018] As described above, the present invention has the following beneficial effects: compared with the prior art, the rapid pressure relief type hydraulically controlled one-way valve involved in the present invention creatively adopts the main valve core and the auxiliary valve core arranged coaxially front and back to cooperate, and forms an active cavity between the main valve core, the auxiliary valve core and the valve body, forms a sealed cavity between the active cavity and the A port, and arranges a pressure difference sealing member in the sealed cavity. During the actual pressure relief process, when the K port is pressurized to push the valve stem, the valve stem first pushes the auxiliary valve core to open the active cavity and the PA port. At this time, the locked high-pressure liquid in the active cavity is quickly depressurized and released to the A port. At the same time, due to The connecting hole is set, and the liquid in the sealing chamber is relieved to the movable chamber. In the process of pressure relief, the front and rear sides of the sealing member are subjected to the high pressure of the sealing chamber and the low pressure of the movable chamber, and the sealing member quickly blocks the flow hole, thereby realizing the rapid discharge of the high-pressure liquid locked in the movable chamber and other chambers to the PA port. When applied to the push hydraulic system, at the moment of operating the hydraulic cylinder to extend the action, the rod chamber return liquid channel can be quickly opened, avoiding the disadvantage of instantaneous pressure holding in the rod chamber of the hydraulic cylinder due to the slow opening of the hydraulic control one-way valve, thereby solving the problem of frequent opening of the safety valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for use in the embodiment: Figure 1 It is a structural schematic diagram of a specific embodiment 1 of the rapid pressure relief hydraulically controlled one-way valve of the present invention; Figure 2 for Figure 1 A half-section view of; Figure 3 for Figure 2 The distribution diagram of chambers and pore systems in the Figure 4 for Figure 2 Structural sectional view of the valve body in FIG. Figure 5 for Figure 2 Schematic diagram of the structure of the middle valve sleeve; Figure 6 for Figure 5 A half-section view of Figure 7 for Figure 2 Structural schematic diagram of the middle joint seat; Figure 8 for Figure 2 Schematic diagram of the assembly structure of the middle valve core assembly and the valve stem; Fig. 9 for Figure 8 A half-section view of Fig.10 for Figure 8 Schematic diagram of the structure of the middle valve stem; Fig.11 Figure 2 A schematic diagram of the structure of the movable baffle; Fig.12 for Fig.11 A half-section view of Fig.13 It is a structural schematic diagram of a specific embodiment 2 of the rapid pressure relief hydraulically controlled one-way valve of the present invention; Fig.14 It is a structural schematic diagram of a specific embodiment 3 of the rapid pressure relief hydraulically controlled one-way valve of the present invention; Fig.15 It is a structural schematic diagram of a specific embodiment 4 of the rapid pressure relief hydraulically controlled one-way valve of the present invention;.

[0020] Description of reference numerals: 1-valve housing; 11-PA port; 12-A port; 13-K port; 14-mounting hole; 15-first internal thread; 16-step surface; 2-valve sleeve; 21-guide hole; 22-rear ring groove; 23-front ring groove; 24-main valve port; 25-blocking edge; 26-first external thread; 27-second internal thread; 3-valve stem; 31-first mating surface; 32-second mating surface; 33-flow groove; 34-third external thread; 4-valve core assembly; 41-main valve core; 42-auxiliary valve core; 43-auxiliary valve port; 44-reset spring; 5-movable baffle; 51-sealing surface; 52-connecting sleeve; 53-third internal thread; 54-light sleeve section; 61-PA cavity; 62-PA side cavity; 63-A cavity; 64-A side cavity; 65-sealed cavity; 66-movable cavity; 67-K cavity; 68-pushing cavity; 69-rod sealing cavity; 71-PA hole, 72-A hole; 73-side through hole; 74-flow hole; 75-straight through hole; 76-flow hole; 81-first sealing ring; 82-second sealing ring; 83-third sealing ring; 84-fourth sealing ring; 85-fifth sealing ring; 86-sixth sealing ring; 91-connector seat; 92-second external thread; 93-plug; 94-nut. DETAILED DESCRIPTION

[0021] In order to make the technical purpose, technical solution and beneficial effects of the present invention clearer, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown herein can be arranged and designed in various different configurations.

[0022] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, which can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0024] A specific embodiment 1 of the rapid pressure relief hydraulically controlled one-way valve of the present invention is as follows: Figures 1 to 12 As shown, the rapid pressure relief hydraulically controlled one-way valve is applied to a push hydraulic system to control the communication between the rod chamber and the rodless chamber of a hydraulic cylinder.

[0025] The hydraulically controlled one-way valve includes a valve body, a valve stem 3, a valve core assembly 4, a return spring 44, and a joint seat 91 arranged in the valve body. The valve body includes a valve shell 1 and a valve sleeve 2 fixedly assembled in the valve shell 1, and a sealing member is movably assembled between the valve sleeve 2 and the joint seat 91.

[0026] Among them, the structure of the valve housing 1 is as follows Figure 1 As shown, it includes a shell, in which a mounting hole 14 is arranged, and the axis of the mounting hole 14 is defined to extend from the back to the front, the diameter of the front hole of the mounting hole 14 is larger than the diameter of the rear hole, and a stepped surface 16 is formed between the two, and the rear hole forms a K port 13 for connecting to the control oil circuit, and two straight holes extending downward and connected to the front hole of the mounting hole 14 are provided at the upper end of the valve housing 1, and the two straight holes are arranged side by side and spaced apart in the front-to-back direction, the straight hole located on the rear side forms a PA port 11 connected to the rodless cavity of the hydraulic cylinder, and the straight hole located on the front side forms an A port 12 connected to the rod cavity of the hydraulic cylinder, and the front end of the inner wall of the front hole of the mounting hole 14 has a first internal thread 15.

[0027] The structure of valve sleeve 2 is as follows Figure 1 As shown, the whole is a sleeve-shaped structure, with a guide hole 21 extending forward and backward opened inside, and a first external thread 26 is provided on the outer wall of the rear end of the guide hole 21. The first external thread 26 and the first internal thread 15 of the valve housing 1 are threadedly matched to realize the fixed connection of the valve sleeve 2 in the valve housing 1. During actual assembly, the valve sleeve 2 is inserted from front to back into the mounting hole 14, and the valve sleeve 2 is rotated to be screwed and fixed in the valve housing 1 until the rear end of the valve sleeve 2 is tightly fitted with the stepped surface 16 of the mounting hole 14. A first sealing ring 81 is provided on the outer wall of the valve sleeve 2 at a position corresponding to the position between the PA port 11 and the A port 12, and a second sealing ring 82 is provided at a position corresponding to the position between the A port 12 and the internal thread, so that the valve sleeve 2 and the valve housing 1 are sealed and assembled. A rear annular groove 22 is formed at a position corresponding to the PA port 11 on the outer wall of the valve sleeve 2. The rear annular groove 22 and the valve housing 1 together form a PA cavity 61 communicating with the PA port 11. A front annular groove 23 is formed at a position corresponding to the A port 12 on the outer wall of the valve sleeve 2. The front annular groove 23 and the valve housing 1 together form an A cavity 63 communicating with the A port 12. A PA hole 71 is formed on the side wall of the valve sleeve 2 corresponding to the rear annular groove 22. The PA hole 71 communicates the inner cavity of the valve sleeve 2 with the PA cavity 61; an A hole 72 is formed on the side wall of the valve sleeve 2 corresponding to the front annular groove 23. The A hole 72 communicates the inner cavity of the valve sleeve 2 with the A cavity 63; a main valve port 24 is formed between the PA hole 71 and the A hole 72 on the inner wall of the valve sleeve 2. The main valve port 24 is a conical main valve port 24 and is arranged forward.

[0028] The joint seat 91 is threadedly connected to the front end of the valve sleeve 2, and a second internal thread 27 is formed on the front inner side wall of the guide hole 21 of the valve sleeve 2, and a second external thread 92 is formed on the rear outer side wall of the joint seat 91. At the same time, a third sealing ring 83 is provided on the connecting surface of the two, and the threaded connection of the two realizes the sealing and fixed connection between the joint seat 91 and the valve sleeve 2. A blocking edge 25 is formed inside the valve sleeve 2 between the joint seat 91 and the A cavity 63, and the blocking edge 25 separates the front and rear sides of the valve sleeve 2.

[0029] The structure of valve stem 3 is as follows Figure 1 As shown, its guide is inserted in the valve housing 1 and the valve sleeve 2. Specifically, the outer diameter of the valve stem 3 gradually decreases from the back to the front. The rear end sealing guide of the valve stem 3 is assembled inside the front hole of the mounting hole 14 of the valve housing 1. A fourth sealing ring 84 is sandwiched between the two, and a K cavity 67 is formed between the valve stem 3 and the K port 13. The valve stem 3 can move forward along the axis of the mounting hole 14 under the pressure of the K port 13. A first mating surface 31 and a second mating surface 32 are provided at the middle position of the valve stem 3, wherein the first mating surface 31 and the second mating surface 32 are both formed by annular step surfaces at different positions of the valve stem 3, and the first mating surface 31 is located behind the second mating surface 32.

[0030] A valve core assembly 4 is provided on the valve stem 3 in a movable sliding sleeve, and the valve core assembly 4 is used to block and open the main valve port 24, thereby controlling the communication between the PA port 11 and the A port 12. The structure of the valve core assembly 4 is shown in FIG. Figure 1 As shown, the valve core assembly 4 includes a main valve core 41 and a secondary valve core 42 which are coaxially arranged and cooperate with front and rear limit stops. In this embodiment, the inner diameter of the secondary valve core 42 is smaller than the inner diameter of the main valve core 41, and the outer diameter of the secondary valve core 42 is smaller than the outer diameter of the main valve core 41. The main valve core 41 is located on the rear side of the secondary valve core 42, and the first mating surface 31 and the second mating surface 32 on the above-mentioned valve stem 3 cooperate with the main valve core 41 and the secondary valve core 42 stop and limit stops respectively.

[0031] The guide sliding sleeve of the main valve core 41 is arranged between the first matching surface 31 and the second matching surface 32 of the valve stem 3. A main conical matching portion is formed at the rear end of the outer wall of the main valve core 41, and the main conical matching portion cooperates with the above-mentioned main valve port 24 to block the PA port 11 and the A port 12. At the same time, a fifth sealing ring 85 is clamped between the front end of the outer wall of the main valve core 41 and the inner wall of the valve sleeve 2. The fifth sealing ring 85 is located in front of the A hole 72. Through the arrangement of the main valve core 41, an A side cavity 64 connected to the A hole 72 is formed between the outer wall of the main valve core 41 and the valve sleeve 2, and a PA side cavity 62 connected to the PA hole 71 is enclosed between the rear side wall of the main valve core 41 and the valve sleeve 2. When the valve stem 3 moves forward, the first matching surface 31 pushes the main valve core 41 to move forward, thereby opening the main valve port 24, and then realizing the connection between the PA side cavity 62 and the A side cavity 64. At the same time, a secondary valve port 43 is formed at the front end of the inner side wall of the main valve core 41, and the secondary valve port 43 is a conical secondary valve port 43. A connecting structure connecting the secondary valve port 43 and the PA port 11 is provided on the valve stem 3 and / or the main valve core 41. Specifically in this embodiment, the connecting structure is a flow groove 33 provided on the outer side wall of the valve stem 3, and the flow groove 33 extends in the front-to-back direction to connect the secondary valve port 43 and the PA port 11. The front end of the chute is connected to the second mating surface 32, and the rear end is connected to the first mating surface 31, and extends radially outward on the first mating surface 31, thereby connecting the PA side cavity 62 with the secondary valve port 43.

[0032] The guide sliding sleeve of the auxiliary valve core 42 is arranged at the front side position of the second matching surface 32 of the valve stem 3, and the sixth sealing ring 86 is sandwiched between the inner side wall of the auxiliary valve core 42 and the valve stem 3. A conical surface auxiliary matching part is formed at the rear end of the outer side wall of the auxiliary valve core 42, and the conical surface auxiliary matching part is sealed and matched with the auxiliary valve port 43 to block the main valve core 41 and the auxiliary valve core 42. A ring platform is formed on the outer side wall of the auxiliary valve core 42, and the above-mentioned return spring 44 is installed between the ring platform and the blocking edge 25 of the valve sleeve 2. At the same time, the outer side wall of the auxiliary valve core 42, the front side wall of the main valve core 41, the valve sleeve 2, and the blocking edge 25 are surrounded to form an active cavity 66, which is used for the main valve core 41 and the auxiliary valve core 42 to move forward and backward following the valve stem 3.

[0033] The assembly of the main valve core 41 and the auxiliary valve core 42 satisfies: when the second matching surface 32 and the auxiliary valve core 42 are pushed and matched and move forward synchronously, there is a gap between the main valve core 41 and the first matching surface 31. Specifically, under actual working conditions, when the valve stem 3 is moved forward by the force of the K port 13, the return spring 44 on the auxiliary valve core 42 is compressed, and the second matching surface 32 first fits with the auxiliary valve core 42 to push the auxiliary valve core 42 to move forward synchronously. At this time, the main valve core 41 is not in contact with the first matching surface 31; when it continues to move, the active cavity 66 and the PA side cavity 62 can be connected through the flow groove 33 on the valve stem 3; when it continues to move, the main valve core 41 can contact and fit with the first matching surface 31 to push the main valve core 41 to move forward to open the main valve port 24. When the valve stem 3 is released to move backward, the return spring 44 pushes the auxiliary valve core 42 backward in the opposite direction. When it reaches the second mating surface 32, it drives the valve stem 3 to move backward synchronously to block the auxiliary valve port 43, and then drives the main valve core 41 to move backward synchronously to block the main valve port 24, thereby blocking the main valve port 24 and the auxiliary valve port 43.

[0034] In addition, a straight hole 75 connected to the PA cavity 61 is provided on the side wall of the valve sleeve 2 corresponding to the rear annular groove 22 and located on the rear side of the PA hole 71, wherein an inner annular step extending inward is formed on the inner side wall of the valve sleeve 2 at a position between the PA hole 71 and the straight hole 75, and the inner annular step is guided and assembled with the valve stem 3; and the rear side wall of the inner annular step, the rear end of the valve stem 3, the valve sleeve 2 and the valve housing 1 together form a rod sealing cavity 69, and the corresponding straight hole 75 forms an anti-howling hole. The setting of the rod sealing cavity 69 and the anti-howling hole can prevent the rapidly unloaded liquid from directly exerting a large impact on the valve stem 3, thereby preventing vibration and howling during the pressure relief process of the one-way valve.

[0035] In order to achieve rapid pressure relief, in this embodiment, a chamber is formed between the rear end of the joint seat 91 and the front side wall of the blocking edge 25, and the chamber is defined as a sealing chamber 65. At the same time, a side through hole 73 connected to the sealing chamber 65 is provided on the side wall of the front ring groove 23 of the valve sleeve 2 at the front side of the A hole 72. The side through hole 73 is arranged obliquely and connected to the A chamber 63.

[0036] In addition, in order to realize the flow of liquid between the sealing cavity 65 and the movable cavity 66, a communication hole is arranged at an eccentric position on the blocking edge 25, the communication hole extends forward and backward, and the aperture of the communication hole is smaller than the cavity diameters of the movable cavity 66 and the sealing cavity 65. In order to achieve the blocking of the communication hole, a blocking piece is movably installed in the sealing cavity 65, and the blocking piece is reciprocated in the sealing cavity 65 under the pressure difference between the movable cavity 66 and the sealing cavity 65 to block and open the communication hole.

[0037] Specifically, the blocking member is a movable baffle plate 5 guided and assembled in the sealing cavity 65 along the front-to-back direction, the rear side plate surface of the movable baffle plate 5 is adapted to fit with the front side wall of the blocking edge 25 to form a blocking surface 51 for blocking the flow hole 74, and the front side of the movable baffle plate 5 has an extrusion cavity 68 connected to the sealing cavity 65. That is, the movable baffle 5 is a barrel-shaped structure as a whole, with an extrusion and pushing cavity 68 formed inside, and a flow hole 76 is provided on the side wall. The corresponding bottom surface of the movable baffle 5 forms the above-mentioned blocking surface 51. During the reciprocating movement, the setting of the flow hole 76 enables the sealing cavity 65 to be connected with the extrusion and pushing cavity 68. When the liquid pressure in the active cavity 66 is consistent with the liquid pressure in the sealing cavity 65, the movable baffle 5 can move freely in the sealing cavity 65 without restriction; when the rapid pressure relief causes the liquid pressure in the active cavity 66 to be less than the liquid pressure in the sealing cavity 65, the high-pressure liquid in the sealing cavity 65 enters the active cavity 66 from the flow hole 74. During this process, the pressure in the extrusion and pushing cavity 68 of the movable baffle 5 is consistent with the pressure in the sealing cavity 65, while the pressure on one side of the blocking surface 51 of the movable baffle 5 is reduced due to the pressure relief of the connecting hole. The force generated by the pressure difference on both sides causes the movable baffle 5 to be subjected to the backward extrusion and pushing force and move toward the circulation hole 74, and finally fit on the blocking edge 25 to block the circulation hole 74.

[0038] In order to realize the movable guiding installation of the movable baffle 5, a through hole is opened on the above-mentioned blocking edge 25 at the axial position corresponding to the valve stem 3, and the through hole is arranged along the front-to-back direction through the blocking edge 25. The front end of the above-mentioned valve stem 3 can be inserted forward into the through hole. Correspondingly, an anti-slip portion is provided on the rear side plate surface (i.e., the sealing surface 51) of the movable baffle 5 at the coaxial position corresponding to the valve stem 3, and the anti-slip portion is matched with the front end movable sleeve of the valve stem 3 and the anti-slip limiter.

[0039] Preferably, in order to realize the anti-slip assembly of the two and the free movement margin design of the movable baffle 5, the front end of the valve stem 3 is provided with a third external thread 34, and the sealing surface 51 of the movable baffle 5 is provided with a connecting sleeve 52 coaxially arranged with the valve stem 3. The inner hole of the connecting sleeve 52 is formed with a third internal thread 53 and a smooth sleeve section 54 from back to front. After the valve stem 3 is threadedly connected with the connecting sleeve 52, the smooth sleeve section 54 guides the sliding anti-slip assembly. The two threaded ends of the valve stem 3 and the connecting sleeve 52 are both selected to the other side, and the two threads do not contact each other after passing through the threaded mating part. The threaded assembly mode of the valve sleeve 2 and the valve housing 1 is opposite to the threaded assembly mode of the valve stem 3 and the movable baffle 5. In this way, other parts except the valve housing 1 can form an integral threaded plug-in assembly structure, which is convenient for maintenance at the work site.

[0040] The valve core assembly 4 in the valve body adopts a double valve structure of a main valve core 41 and a secondary valve core 42. The main valve core 41 controls the opening and closing of the main valve port 24 between the PA side chamber 62 and the A side chamber 64, and the secondary valve core 42 controls the opening and closing of the secondary valve port 43 between the PA side chamber 62 and the active chamber 66; the reset spring 44 can reset the valve core assembly 4 in time when it is in a closed state.

[0041] Working principle: When the push hydraulic system is operated to make the hydraulic cylinder contract to perform a push and slide action, the PA port 11 is pressurized, the PA cavity 61 is pressurized, the liquid flows from the PA port 11 into the PA cavity 61, and enters the PA side cavity 62 through the PA hole 71. Under the action of the liquid pressure, the main valve core 41 and the auxiliary valve core 42 overcome the force of the return spring 44 and begin to move right, and the main valve port 24 and the auxiliary valve port 43 are opened; most of the liquid flows from the PA side cavity 62 through the main valve port 24 into the A side cavity 64, and then enters the A cavity 63 through the A hole 72, and then is discharged from the A cavity 63 through the A port 12; a small part The liquid enters the active chamber 66 through the chute on the valve stem 3. At the same time, the high-pressure liquid in the active chamber 66 is squeezed by the valve core through the flow hole 74 and pushes the active baffle 5 to be pressed into the sealing chamber 65. The liquid entering the sealing chamber 65 enters the A chamber 63 through the side through hole 73. When the hydraulic cylinder completes the contraction action, the high-pressure liquid in the cavities of all hydraulic components connected between the A side chamber 64, the active chamber 66 and the rod chamber of the hydraulic cylinder is locked by the main valve core 41 and the auxiliary valve core 42, and the liquid in each chamber such as the active chamber 66, the A side chamber 64, the sealing chamber 65, etc. is at equal pressure.

[0042] When the hydraulic system is operated to extend the hydraulic cylinder to perform the rack pulling action, the K port 13 is pressurized, the K chamber 67 is pressurized, and the pressure in the K chamber 67 also pushes the valve stem 3 forward. The second matching surface 32 of the valve stem 3 first pushes the auxiliary valve core 42 forward, so that the auxiliary valve port 43 between the auxiliary valve core 42 and the main valve core 41 is opened, and the flow groove 33 on the valve stem 3 is connected with the active chamber 66, and the PA side chamber 62 is connected with the active chamber 66. When the above-mentioned hydraulic cylinder contraction action is completed in the active chamber 66, the high-pressure liquid locked by the main valve core 41 and the auxiliary valve core 42 begins to flow to the PA side chamber 62 through the active chamber 66, the auxiliary valve port 43, and the flow groove 33, and the pressure of the sealed liquid in the active chamber 66 begins to drop. During the drop, the pressure of the sealing chamber 65 is greatly increased. Due to the pressure of the active chamber 66, the liquid flows from the sealing chamber 65 to the active chamber 66 through the connecting hole. The flowing liquid makes the pressure of the squeezing chamber 68 of the active baffle 5 higher than the pressure on the side of the blocking surface 51. Under the force generated by the liquid pressure difference, the active baffle 5 will slide backward until the flow hole 74 is blocked, thereby blocking the passage between the sealing chamber 65 and the active chamber 66, so that the pressure of the active chamber 66 can be quickly reduced; under the continuous action of the hydraulic pressure of the K port 13, the valve stem 3 continues to move forward, and the first matching surface 31 of the valve stem 3 pushes the main valve core 41 forward, so that the PA side chamber 62 and the A side chamber 64 can be quickly opened, so that the K port 13 can quickly open the main and auxiliary valve cores 42 under the condition of low control pressure. For the push hydraulic system, at the moment of operating the hydraulic cylinder to extend, the rod chamber return liquid channel can be quickly opened, avoiding the disadvantage of instantaneous pressure holding in the hydraulic cylinder rod chamber due to the slow opening of the hydraulic control one-way valve, thereby solving the problem of frequent opening of the safety valve.

[0043] Principle of quick pressure relief: Compared with the existing single valve core setting mode, since the active chamber 66 of the existing single valve core is connected to the A port 12, there is high-pressure liquid inside it. If the valve port needs to be opened, the single valve core needs to overcome the reverse force of the high-pressure liquid in the active chamber 66 and the high-pressure liquid pressure on the A port 12 side. At this time, the pressure on the K chamber 67 side that acts instantaneously needs to be high enough to achieve it. In the present application, through the structure of the main valve core 41 and the auxiliary valve core 42, the active chamber 66 is connected to the PA side through the auxiliary valve port 43. When pressure relief is required, the auxiliary valve port 43 can be opened at the moment when the pressure of the K chamber 67 increases by a small amplitude, that is, the high-pressure liquid in the active chamber 66 is released to the PA port 11 to avoid pressure holding. The subsequent pressure increase of the K chamber 67 can push the main valve core 41 to open the valve port (at this time, the liquid pressure in the active chamber 66 is the same as the liquid pressure of the PA port 11.) In this way, the K port 13 can quickly open the main and auxiliary valve cores 42 under the condition of low control pressure.

[0044] Embodiment 2 is different from Embodiment 1 in that Fig.13 As shown, the front end of the valve sleeve 2 can be connected with a plug 93.

[0045] Embodiment 3 is different from Embodiment 1 in that Fig.14 As shown, the auxiliary valve core 42 is a fixed structure directly fixedly connected to the tail end of the valve stem 3. In addition, a groove is set on the cylindrical surface of the rear side of the auxiliary valve core 42 that matches the inner hole of the main valve core 41 to form the above-mentioned flow groove 33, and the movable baffle 5 is designed to be directly assembled with the perforated guide.

[0046] Embodiment 4 is different from Embodiment 1 in that Fig.15 As shown, the anti-slip structure design of the valve stem 3 and the movable baffle 5 is designed by passing the valve stem 3 through the connecting sleeve 52 of the movable baffle 5, and then using the nut 94 to form an integral threaded plug-in component structure. The valve stem 3 and the movable baffle 5 are sliding mating surfaces. This structure also has the functional characteristics of sealing the sealing cavity 65 behind the valve core.

[0047] In other embodiments, the plugging member may also be designed as a flip plug arranged on one side of the flow hole 74, the plugging member may open the flow hole 74 by flipping forward, and may fit into the flow hole 74 by flipping backward. It may also be designed as a plugging rod inserted into the flow hole 74, with a hole for liquid circulation formed on the side wall of the plugging rod, a boss formed on the front side of the plugging rod, a squeezing cavity 68 formed on the front side of the boss, and a plugging surface 51 formed on the rear side.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate but not limit the technical solutions of the present invention, and any equivalent substitutions of the present invention and any modifications or partial substitutions that do not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A quick pressure relief hydraulically controlled one-way valve, comprising a valve body, a valve cavity extending forward and backward in the valve body, a valve stem guided in the valve cavity, a PA port, an A port and a K port on the valve body, a main valve port formed between the PA port and the A port in the valve cavity, the rear end of which is connected to the K port, a valve core assembly sleeved on the valve stem, the rear end of the valve core assembly cooperates with the main valve port to separate the PA port and the A port, a reset spring is installed on the front end of the valve core assembly, characterized in that: The valve core assembly includes a main valve core and a secondary valve core which are coaxially arranged and matched with front and rear limit stops. The main valve core is located at the rear side of the secondary valve core. The valve stem is provided with a first matching surface which is matched with the main valve core to push forward, and also has a second matching surface which is matched with the secondary valve core to push forward. When the second matching surface is matched with the secondary valve core to push and move synchronously, there is a gap between the main valve core and the first matching surface. An active cavity connected with the PA port is formed between the main valve core, the secondary valve core and the valve body. An secondary valve port is arranged between the secondary valve core and the main valve core to separate the active cavity from the PA port. The valve body is also provided with a sealing cavity which is connected with the A port. A connecting hole is connected between the sealing cavity and the active cavity. The aperture of the connecting hole is smaller than the aperture of the active cavity and the sealing cavity. A sealing member is movably assembled in the sealing cavity. The sealing member is subjected to the pressure difference between the active cavity and the sealing cavity and reciprocates in the sealing cavity to block the connecting hole and open the connecting hole.

2. The rapid pressure relief hydraulically controlled one-way valve according to claim 1, characterized in that: A plugging edge is provided at the front end of the valve stem in the valve cavity, the cavity between the plugging edge and the valve core assembly constitutes an active cavity, a sealing cavity is formed between the front side of the plugging edge and the valve body, and the communicating hole is arranged on the plugging edge.

3. The rapid pressure relief hydraulically controlled one-way valve according to claim 2, characterized in that: The blocking member is a movable baffle plate guided and assembled in the sealing cavity, the rear side plate surface of the movable baffle plate is adapted to fit with the front side wall of the blocking edge to form a blocking surface for blocking the flow hole, and the front side of the movable baffle plate has an extrusion cavity connected to the sealing cavity.

4. The rapid pressure relief hydraulically controlled one-way valve according to claim 3, characterized in that: The blocking edge is provided with a through hole for the front end of the valve stem to pass through, and the rear side plate of the movable baffle is provided with an anti-slip portion at a coaxial position corresponding to the valve stem, and the anti-slip portion cooperates with the front end movable sleeve of the valve stem and the anti-slip limiter.

5. The rapid pressure relief hydraulically controlled one-way valve according to claim 4, characterized in that: The front end of the valve stem has an external thread, and a connecting sleeve is provided on the rear side wall of the movable baffle. The inner hole of the connecting sleeve is formed with an internal thread section and a smooth sleeve section from back to front. After the valve stem is threadedly connected to the connecting sleeve, it is guided by the smooth sleeve section to slide and prevent disengagement.

6. The rapid pressure relief hydraulically controlled one-way valve according to claim 1, characterized in that: The valve stem and / or the main valve core is provided with a communication structure connecting the auxiliary valve port and the PA port.

7. The rapid pressure relief hydraulically controlled one-way valve according to claim 9, characterized in that: The communication structure is a flow groove formed on the outer side wall of the valve stem, and the flow groove extends in the front-to-back direction to connect the auxiliary valve port and the PA port.

8. The rapid pressure relief hydraulically controlled one-way valve according to claim 2, characterized in that: The valve body includes a valve shell and a valve sleeve sealed in the valve shell, the valve sleeve has a PA hole connected to the PA port, an A hole connected to the A port, and a guide hole connected to the K port, the valve stem is installed in the guide hole, and the front end of the valve sleeve has a blocking edge formed by bending inward, and the blocking edge constitutes the blocking edge.

9. The rapid pressure relief hydraulically controlled one-way valve according to claim 8, characterized in that: The side wall of the valve sleeve is also provided with a side through hole connecting the A port and the sealing cavity.

10. The rapid pressure relief hydraulically controlled one-way valve according to claim 8, characterized in that: The rear end of the inner side wall of the valve sleeve is provided with an inner annular step matched with the valve stem guide, and an anti-whistling hole connecting the PA port and the guide hole is provided on the side wall of the valve sleeve behind the inner annular step.

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