A bidirectional buffer logic control valve for hydraulic support

Abstract

The present invention belongs to the technical field of hydraulic equipment, and in particular relates to a bidirectional buffer logic control valve for a hydraulic support. The first buffer assembly and the second buffer assembly of the control valve are both embedded in the buffer channel. The first buffer assembly includes a first screw plug and a valve seat. The first screw plug is fixed to the port of the buffer channel on the side of the liquid inlet. The valve seat is located on the side of the tail of the first screw plug, and a first spring is provided between the first screw plug and the valve seat. The second buffer assembly includes a second screw plug and a valve core. The second screw plug is fixed to the port of the buffer channel on the side of the liquid return port. The valve core is located on the side of the tail of the second screw plug, and a second spring is provided between the second screw plug and the valve core. The valve seat and the valve core can contact to cut off the buffer channel. Therefore, the present invention realizes the effects of cutting off and throttling the inlet circuit of the pipeline respectively through the sealing cooperation between the valve seat and the valve core. Moreover, the double spring buffering strengthens the impact resistance of the internal structure of the valve body, and the valve seat and valve core structure are not easily damaged.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic equipment, and in particular relates to a bidirectional buffer logic control valve for a hydraulic support. Background Art

[0002] With the acceleration of intelligent coal mines and the rapid development of hydraulic support control technology, the requirements for control components are becoming increasingly stringent, which in turn places further demands on the hydraulic control valves used in equipment. In many applications, the pipelines on the hydraulic support need to achieve forward cutoff and reverse throttling, or to reduce the control instability caused by the pulse effect of the liquid supply. The hydraulic pipeline control valve is a hydraulic component that can achieve reverse throttling, anti-pulse effect, and buffering.

[0003] However, existing hydraulic pipeline control valves have complex internal structures and high manufacturing costs. When subjected to uncontrolled or unbuffered high-pressure liquid pressure in the high-pressure environment of the working face, the mechanical equipment controlled by the hydraulic pipelines in which they are located will undergo sudden and drastic movements, posing a safety threat to equipment and personnel underground. Furthermore, the internal structure of the control valve can be damaged by the impact, leading to seal failure and potentially posing operational hazards to various underground mechanical equipment, including hydraulic supports, and seriously impacting the normal operation of the coal mining face. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a bidirectional buffer logic control valve for a hydraulic support, thereby solving the technical problems.

[0006] (2) Technical solution

[0007] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] An embodiment of the present invention provides a bidirectional buffer logic control valve for a hydraulic support, comprising a valve body, and also comprising a first buffer assembly and a second buffer assembly; a buffer channel is provided on the valve body, the buffer channel runs through the valve body, a liquid inlet and two liquid return ports connected to the buffer channel are provided on the valve body, and the first buffer assembly and the second buffer assembly are both embedded in the buffer channel; the first buffer assembly comprises a first screw plug and a valve seat, the first screw plug is fixed to the port of the buffer channel on the liquid inlet side, the valve seat is located on the side of the tail of the first screw plug, and a first spring is arranged between the first screw plug and the valve seat; the second buffer assembly comprises a second screw plug and a valve core, the second screw plug is fixed to the port of the buffer channel on the side of the liquid return port, the valve core is located on the side of the tail of the second screw plug, and a second spring is arranged between the second screw plug and the valve core; the valve seat and the valve core can contact to cut off the buffer channel.

[0009] Furthermore, the buffer channel includes a first through hole, a second through hole and a third through hole connected in sequence, the third through hole is connected to the port of the buffer channel on the side of the return liquid port, and the diameter of the second through hole is smaller than the diameter of the first through hole and the diameter of the third through hole; the valve seat includes a connected valve seat head and a valve seat tail, the diameter of the valve seat head is larger than the diameter of the valve seat tail, the diameter of the valve seat head is adapted to the diameter of the first through hole, the diameter of the valve seat tail is adapted to the diameter of the second through hole, when the valve seat head contacts the tail of the first screw plug, the position of the valve seat is the first position, and when the valve seat head is stuck at the connection between the first through hole and the second through hole, the position of the valve seat is The valve core is in the second position, and the movement range of the valve seat is the area between the first position and the second position; the valve core includes a connected valve core head and a valve core clamping portion, the diameter of the valve core clamping portion is larger than the diameter of the valve core head, the diameter of the valve core head is adapted to the diameter of the second through hole, the diameter of the valve core clamping portion is larger than the diameter of the second through hole and is less than or equal to the diameter of the third through hole. When the valve seat is in the second position and the valve core contacts the valve seat, the position of the valve core is the third position. When the valve core clamping portion is clamped at the connection between the second through hole and the third through hole, the position of the valve core is the fourth position, and the movement range of the valve core is the area between the third position and the fourth position.

[0010] Furthermore, the tail of the second screw plug is connected to the buffer channel, the tail of the second screw plug is located in the third through hole, and the diameter of the second screw plug is adapted to the diameter of the third through hole; the valve core also includes a valve core tail connected to the valve core clamping portion, the valve core tail is located on the side of the valve core clamping portion away from the valve core head, the diameter of the valve core tail is smaller than the diameter of the valve core clamping portion, one end of the second spring is sleeved on the valve core tail and abuts against the valve core clamping portion, and the other end of the second spring abuts against the tail of the second screw plug to buffer the valve core.

[0011] Furthermore, the buffer channel also includes a fourth through hole connected to the first through hole, the fourth through hole is located on the side of the first through hole away from the second through hole, and the fourth through hole is connected to the port of the buffer channel on the liquid inlet side; the first screw plug includes a fixing portion connected to the tail of the first screw plug, the fixing portion is located on the side of the tail of the first screw plug away from the valve seat, the diameter of the fixing portion is larger than the diameter of the tail of the first screw plug, the fixing portion and the tail of the first screw plug are both located in the fourth through hole, and the diameter of the fixing portion is adapted to the diameter of the fourth through hole; the first screw plug, the valve seat and the buffer channel enclose a liquid inlet space, the liquid inlet is always connected to the liquid inlet space through the liquid inlet channel, and the valve seat will be subjected to the thrust of the high-pressure liquid entering the liquid inlet space and tend to move toward the valve core.

[0012] Furthermore, the valve seat, valve core and buffer channel enclose a liquid return space, and the two liquid return ports are always connected to the liquid return space through their respective liquid return channels. The valve seat will be thrust by the high-pressure liquid entering the liquid return space and tend to move toward the first screw plug.

[0013] Furthermore, a liquid hole is opened at the tail of the valve seat, and the front side of the valve core head is a conical surface. When the valve seat contacts the valve core, part of the valve core head at the conical surface extends into the liquid hole, so that the valve seat and the valve core form a hard seal.

[0014] Furthermore, a first groove is formed at the tail of the first screw plug, and a second groove is formed at the head of the valve seat. Both ends of the first spring respectively abut against the first groove and the second groove to buffer the valve seat.

[0015] Furthermore, a liquid passage groove is provided on the end surface of the valve seat head portion, the liquid passage groove is communicated with the second groove, and the second groove is communicated with the liquid passage hole.

[0016] Furthermore, an inner cavity is opened in the valve core, and the side of the inner cavity close to the second screw plug is opened to connect the inner cavity with the buffer channel; three fifth through holes are opened on the side wall of the valve core head, and the three fifth through holes are evenly distributed circumferentially around the valve core head; when the second buffer assembly is arranged in the buffer channel, a fifth through hole on the valve core is connected to one of the return liquid channels.

[0017] Furthermore, a section is provided on the outer side wall of the valve core head portion at the fifth through hole so that a distance exists between the valve core head portion at the fifth through hole and the inner wall of the second through hole.

[0018] (3) Beneficial effects

[0019] The beneficial effects of the present invention are:

[0020] The present invention relates to a bidirectional buffer logic control valve for a hydraulic support. A buffer channel is defined on the valve body, with a first buffer assembly and a second buffer assembly embedded within the buffer channel. Furthermore, the valve body is provided with a liquid inlet and a liquid return port that communicate with the buffer channel. The first buffer assembly includes a first screw plug and a valve seat, with a first spring interposed between the first screw plug and the valve seat. The second buffer assembly includes a second screw plug and a valve core, with a second spring interposed between the second screw plug and the valve core. The valve seat and valve core can contact to block the buffer channel.

[0021] When the pressure of the pipeline connected to the liquid inlet is high, the valve seat and the valve core are sealed, the logic control valve is closed, and the pipeline is cut off. When the pressure of the return liquid port is high, the valve seat moves under the action of pressure and contacts the first screw plug, the valve seat and the valve core are separated, the logic control valve is opened, and the pressure of the pipeline connected to the return liquid port can slowly drop until the pressure of the pipeline connected to the liquid inlet and the return liquid port is balanced, and the logic control valve is closed again.

[0022] Compared to existing technologies, the present invention utilizes a sealed connection between the valve seat and valve core within the valve body to achieve both shutoff and throttling of the pipeline's inlet circuit based on the controlled hydraulic line pressure. Furthermore, the dual-spring buffer formed by the first and second springs effectively mitigates pressure surges within the high-pressure pipeline, enhancing the valve body's internal shock resistance and preventing damage to the valve seat and valve core. The logic control valve of the present invention boasts a simple overall structure, easy assembly and disassembly, a reliable sealing mechanism, and precise control of pipeline pressure and flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of a bidirectional buffer logic control valve for a hydraulic support;

[0024] Figure 2 Schematic diagram of the cross-sectional structure of the valve body;

[0025] Figure 3 is a schematic cross-sectional structural diagram of the first buffer component;

[0026] Figure 4 is a schematic cross-sectional structural diagram of the second buffer assembly;

[0027] Figure 5 Schematic diagram of the cross-sectional structure of the valve core.

[0028] [Description of Reference Numerals]

[0029] 1: valve body; 11: buffer channel; 111: first through hole; 112: second through hole; 113: third through hole; 114: fourth through hole; 115: liquid inlet space; 116: liquid return space; 12: liquid inlet; 13: liquid return port; 14: liquid inlet channel; 15: liquid return channel;

[0030] 2: First buffer assembly; 21: First screw plug; 211: First screw plug tail; 2111: First groove; 212: Fixing portion; 22: Valve seat; 221: Valve seat head; 2211: Second groove; 2212: Liquid passage groove; 222: Valve seat tail; 2221: Liquid passage hole; 23: First spring;

[0031] 3: Second buffer assembly; 31: Second screw plug; 311: Tail of second screw plug; 32: Valve core; 321: Valve core head; 3211: Fifth through hole; 3212: Cut surface; 322: Valve core clamping portion; 323: Valve core tail; 324: Inner cavity; 33: Second spring. DETAILED DESCRIPTION

[0032] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0033] like Figure 1-5 As shown, the present invention provides a bidirectional buffer logic control valve for a hydraulic support, comprising a valve body 1, a first buffer assembly 2 and a second buffer assembly 3.

[0034] like Figure 1 、 Figure 2 As shown, the valve body 1 is provided with a buffer channel 11, a liquid inlet 12 connected to the buffer channel 11, and two liquid return ports 13. The buffer channel 11 runs through the valve body 1, the liquid inlet 12 is connected to the buffer channel 11 through the liquid inlet channel 14, and the two liquid return ports 13 are connected to the buffer channel 11 through their respective liquid return channels 15. Among them, the liquid inlet 12 and one of the liquid return ports 13 are not on the same side wall of the valve body 1 as the end of the buffer channel 11, while the other liquid return port 13 is on the same side wall of the valve body 1 as the end of the buffer channel 11. The liquid return channel 15 connected to the liquid return port 13 on the same side wall of the valve body 1 as the end of the buffer channel 11 is L-shaped. The first buffer assembly 2 and the second buffer assembly 3 are both embedded in the buffer channel 11.

[0035] like Figure 1 、 Figure 3 As shown, the first buffer assembly 2 includes a first screw plug 21 and a valve seat 22. The first screw plug 21 is fixed to the port of the buffer channel 11 on one side of the liquid inlet 12. The valve seat 22 is located on one side of the tail 211 of the first screw plug. A first spring 23 is arranged between the first screw plug 21 and the valve seat 22. When the first buffer assembly 2 is installed in the buffer channel 11, the first spring 23 is in a compressed state.

[0036] like Figure 1 、 Figure 4 As shown, the second buffer assembly 3 includes a second screw plug 31 and a valve core 32. The second screw plug 31 is fixed to the port of the buffer channel 11 on the side of the return liquid port 13. The valve core 32 is located on the side of the tail 311 of the second screw plug. A second spring 33 is arranged between the second screw plug 31 and the valve core 32. When the second buffer assembly 3 is installed in the buffer channel 11, the second spring 33 is in a compressed state.

[0037] When the bidirectional buffer logic control valve for the hydraulic support is not working, that is, no liquid enters, the first spring 23 and the second spring 33 are both in a compressed state. At this time, the valve seat 22 and the valve core 32 are respectively pushed by the first spring 23 and the second spring 33, thereby contacting and cutting off the buffer channel 11. At this time, the bidirectional buffer logic control valve for the hydraulic support is in a closed state.

[0038] During operation of the bidirectional buffer logic control valve for a hydraulic support, the first spring 23 and second spring 33 effectively buffer the pulsating pressure within the high-pressure pipeline. Specifically, the second spring 33 in the second buffer assembly 3 effectively offsets the impact of transient high-pressure liquid from the pipeline connected to the liquid inlet 12 on the valve core 32, while the first spring 23 in the first buffer assembly 2 effectively offsets the impact of transient high-pressure liquid from the pipeline connected to the liquid return port 13 on the valve seat 22. This reduces damage caused by impacts between the valve core 32 and the second screw plug 31, and between the valve seat 22 and the first screw plug 21, thereby preventing contamination of the pipeline by falling debris.

[0039] It should be noted that the “high pressure” in the so-called high-pressure liquid refers to a relatively high pressure relative to the pressure of the liquid at other locations in the pipeline.

[0040] Specifically, if Figure 2 As shown, the buffer channel 11 includes a fourth through hole 114, a first through hole 111, a second through hole 112 and a third through hole 113 connected in sequence, the fourth through hole 114 is located on the side of the first through hole 111 away from the second through hole 112, the fourth through hole 114 is connected to the port of the buffer channel 11 on the side of the liquid inlet 12, the third through hole 113 is connected to the port of the buffer channel 11 on the side of the liquid return port 13, and the diameter of the second through hole 112 is smaller than the diameter of the first through hole 111 and the diameter of the third through hole 113.

[0041] like Figure 1 、 Figure 3 As shown, the first screw plug 21 includes a fixing portion 212 connected to the first screw plug tail 211, the fixing portion 212 is located on the side of the first screw plug tail 211 away from the valve seat 22, the diameter of the fixing portion 212 is larger than the diameter of the first screw plug tail 211, the fixing portion 212 and the first screw plug tail 211 are both located in the fourth through hole 114, and the diameter of the fixing portion 212 is adapted to the diameter of the fourth through hole 114.

[0042] The valve seat 22 includes a connected valve seat head 221 and a valve seat tail 222 . The diameter of the valve seat head 221 is larger than the diameter of the valve seat tail 222 . The diameter of the valve seat head 221 matches the diameter of the first through hole 111 , and the diameter of the valve seat tail 222 matches the diameter of the second through hole 112 .

[0043] The first screw plug 21 , the valve seat 22 and the buffer channel 11 enclose a liquid inlet space 115 , and the liquid inlet 12 is always connected to the liquid inlet space 115 through the liquid inlet channel 14 . The valve seat 22 will be thrust by the high-pressure liquid entering the liquid inlet space 115 and tend to move toward the valve core 32 .

[0044] The first screw plug tail portion 211 defines a first groove 2111 , the valve seat head portion 221 defines a second groove 2211 , and both ends of the first spring 23 respectively abut against the first groove 2111 and the second groove 2211 to cushion the valve seat 22 .

[0045] When the valve seat head 221 contacts the first screw plug tail 211, the position of the valve seat 22 is the first position. When the valve seat head 221 is stuck at the connection between the first through hole 111 and the second through hole 112, the position of the valve seat 22 is the second position. The moving range of the valve seat 22 is the area between the first position and the second position.

[0046] like Figure 1 、 Figure 4 As shown, the valve core 32 includes a valve core head 321, a valve core clamping portion 322, and a valve core tail 323. The valve core tail 323 is located on the side of the valve core clamping portion 322 away from the valve core head 321. The diameter of the valve core tail 323 is smaller than the diameter of the valve core clamping portion 322, and the diameter of the valve core clamping portion 322 is larger than the diameter of the valve core head 321. The diameter of the valve core head 321 is adapted to the diameter of the second through hole 112, and the diameter of the valve core clamping portion 322 is larger than the diameter of the second through hole 112 and smaller than or equal to the diameter of the third through hole 113.

[0047] The second screw plug tail portion 311 is connected to the buffer channel 11 . The second screw plug tail portion 311 is located in the third through hole 113 . The diameter of the second screw plug tail portion 311 matches the diameter of the third through hole 113 .

[0048] The valve seat 22, the valve core 32 and the buffer channel 11 enclose a liquid return space 116. The two liquid return ports 13 are always connected to the liquid return space 116 through their respective liquid return channels 15. The valve seat 22 will be thrust by the high-pressure liquid entering the liquid return space 116 and tend to move toward the first screw plug 21, causing the valve seat 22 and the valve core 32 to separate.

[0049] One end of the second spring 33 is sleeved on the valve core tail portion 323 and abuts against the valve core clamping portion 322 , and the other end of the second spring 33 abuts against the second screw plug tail portion 311 to buffer the valve core 32 .

[0050] When the valve seat 22 is in the second position and the valve core 32 is in contact with the valve seat 22, the position of the valve core 32 is the third position. When the valve core clamping portion 322 is clamped at the connection between the second through hole 112 and the third through hole 113, the position of the valve core 32 is the fourth position. The moving range of the valve core 32 is the area between the third position and the fourth position.

[0051] Preferably, the valve seat tail portion 222 defines a liquid passage hole 2221, and the front side of the valve core head 321 is a conical surface. When the valve seat 22 contacts the valve core 32, the portion of the conical surface of the valve core head 321 extends into the liquid passage hole 2221, forming a hard seal between the valve seat 22 and the valve core 32. The use of a hard seal can extend the service life, enhance anti-contamination capabilities, make the valve seat 22 and valve core 32 more resistant to cyclic impact, and eliminate the seal failure caused by the use of organic sealing gaskets.

[0052] In addition, the end surface of the valve seat head 221 is provided with a liquid passage groove 2212, which communicates with the second groove 2211, which in turn communicates with the liquid passage hole 2221. Liquid entering from the liquid return port 13 can enter the liquid return space 116 through the liquid return channel 15, then sequentially enter the second groove 2211 and the liquid passage groove 2212 through the liquid passage hole 2221, and finally enter the liquid inlet space 115 to balance the liquid pressure. The size of the liquid passage groove 2212 can be adjusted during installation based on the operating environment to enable the logic control valve to precisely control the speed of pressure changes.

[0053] An inner cavity 324 is provided in the valve core 32, and one side of the inner cavity 324 close to the second screw plug 31 is open so that the inner cavity 324 is connected to the buffer channel 11. Three fifth through holes 3211 are provided on the side wall of the valve core head 321, and the three fifth through holes 3211 are evenly distributed around the circumference of the valve core head 321. When the second buffer assembly 3 is disposed in the buffer channel 11, one of the fifth through holes 3211 on the valve core 32 is connected to one of the return liquid channels 15. When the valve core 32 moves toward the second screw plug 31, the liquid and gas between the valve core 32 and the second screw plug 31 can flow out from the fifth through hole 3211, so that the valve core 32 is only subjected to the elastic force applied by the second spring 33 inside the second buffer assembly 3.

[0054] Preferably, if Figure 5 As shown, the outer wall of the valve core head 321 at the fifth through hole 3211 is provided with a cut surface 3212 so that there is a distance between the valve core head 321 at the fifth through hole 3211 and the inner wall of the second through hole 112 to ensure that the fifth through hole 3211 is connected to one of the return liquid channels 15.

[0055] Working principle: The present invention is controlled by pipeline pressure. When the pressure of the liquid inlet 12 is high, the valve seat 22 contacts the valve core 32 and produces a hard seal to cut off the buffer channel 11, that is, the logic control valve is closed and the pipeline is cut off. When the pressure of the return liquid port 13 is high, the valve seat 22 moves toward the first screw plug 21 under the action of pressure and contacts the end face of the tail of the first screw plug 211. Under the action of pressure, the liquid in the pipeline flows from the return liquid port 13 into the return liquid channel 15, the return liquid space 116, the liquid hole 2221, the second groove 2211, the liquid groove 2212 and the liquid inlet space 115 in sequence. Through the flow-limiting effect of the liquid hole 2221 and the liquid groove 2212, the pressure of the pipeline connected to the return liquid port 13 can slowly drop until the pressure of the pipelines at both ends is balanced and the logic control valve is closed.

[0056] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0057] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0059] In the description of this specification, the terms "one embodiment", "some embodiments", "embodiments", "examples", "specific examples" or "some examples" refer to the specific features, structures, materials or characteristics described in conjunction with the embodiment or example and included in at least one embodiment or example of the present invention. In this specification, the schematic expressions 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. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0060] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A bidirectional buffer logic control valve for a hydraulic support, comprising a valve body (1), characterized in that: It also includes a first buffer component (2) and a second buffer component (3); The valve body (1) is provided with a buffer channel (11), the buffer channel (11) runs through the valve body (1), the valve body (1) is provided with a liquid inlet (12) and two liquid return ports (13) communicating with the buffer channel (11), and the first buffer component (2) and the second buffer component (3) are both embedded in the buffer channel (11); The first buffer assembly (2) comprises a first screw plug (21) and a valve seat (22), wherein the first screw plug (21) is fixed to a port of the buffer channel (11) on one side of the liquid inlet (12), and the valve seat (22) is located on one side of a tail portion (211) of the first screw plug, and a first spring (23) is provided between the first screw plug (21) and the valve seat (22); The second buffer assembly (3) comprises a second screw plug (31) and a valve core (32), wherein the second screw plug (31) is fixed to a port of the buffer channel (11) on one side of the liquid return port (13), and the valve core (32) is located on one side of the tail portion (311) of the second screw plug, and a second spring (33) is provided between the second screw plug (31) and the valve core (32); The buffer channel (11) comprises a first through hole (111), a second through hole (112), and a third through hole (113) connected in sequence, the third through hole (113) being in communication with a port of the buffer channel (11) on one side of the liquid return port (13), and the diameter of the second through hole (112) being smaller than the diameters of the first through hole (111) and the third through hole (113); The valve seat (22), the valve core (32) and the buffer channel (11) enclose a liquid return space (116), the two liquid return ports (13) are always connected to the liquid return space (116) through their respective liquid return channels (15), and the valve seat (22) is subject to the thrust of the high-pressure liquid entering the liquid return space (116) and has a tendency to move toward the first screw plug (21); An inner cavity (324) is provided in the valve core (32), and a side of the inner cavity (324) close to the second screw plug (31) is opened so that the inner cavity (324) is in communication with the buffer channel (11); The valve seat (22) comprises a connected valve seat head (221) and a valve seat tail (222), and a side wall of the valve core head (321) is provided with three fifth through holes (3211), and the three fifth through holes (3211) are evenly distributed in the circumferential direction of the valve core head (321); When the second buffer assembly (3) is arranged in the buffer channel (11), one of the fifth through holes (3211) on the valve core (32) is connected to one of the liquid return channels (15); The valve seat (22) and the valve core (32) can contact each other to cut off the buffer channel (11).

2. The bidirectional buffer logic control valve for hydraulic support according to claim 1, characterized in that: The diameter of the valve seat head (221) is larger than the diameter of the valve seat tail (222), the diameter of the valve seat head (221) is adapted to the diameter of the first through hole (111), and the diameter of the valve seat tail (222) is adapted to the diameter of the second through hole (112). When the valve seat head (221) contacts the first screw plug tail (211), the position of the valve seat (22) is the first position. When the valve seat head (221) is stuck at the connection between the first through hole (111) and the second through hole (112), the position of the valve seat (22) is the second position. The moving range of the valve seat (22) is the area between the first position and the second position. The valve core (32) comprises a connected valve core head (321) and a valve core clamping portion (322), the diameter of the valve core clamping portion (322) being larger than the diameter of the valve core head (321), the diameter of the valve core head (321) being adapted to the diameter of the second through hole (112), the diameter of the valve core clamping portion (322) being larger than the diameter of the second through hole (112) and being smaller than or equal to the diameter of the third through hole (113), and when the valve seat (22) is located at the second position and the valve core (32) is in contact with the valve seat (22), the position of the valve core (32) is the third position, and when the valve core clamping portion (322) is clamped at the connection between the second through hole (112) and the third through hole (113), the position of the valve core (32) is the fourth position, and the movable range of the valve core (32) is the area between the third position and the fourth position.

3. The bidirectional buffer logic control valve for hydraulic support according to claim 2, characterized in that: The second screw plug tail (311) is connected to the buffer channel (11), the second screw plug tail (311) is located in the third through hole (113), and the diameter of the second screw plug tail (311) is adapted to the diameter of the third through hole (113); The valve core (32) further includes a valve core tail portion (323) connected to the valve core clamping portion (322), the valve core tail portion (323) being located on a side of the valve core clamping portion (322) away from the valve core head portion (321), the diameter of the valve core tail portion (323) being smaller than the diameter of the valve core clamping portion (322), one end of the second spring (33) being sleeved on the valve core tail portion (323) and abutting against the valve core clamping portion (322), the other end of the second spring (33) abutting against the second screw plug tail portion (311) to buffer the valve core (32).

4. The bidirectional buffer logic control valve for hydraulic support according to claim 2, characterized in that: The buffer channel (11) further comprises a fourth through hole (114) connected to the first through hole (111), the fourth through hole (114) being located on a side of the first through hole (111) away from the second through hole (112), and the fourth through hole (114) being in communication with a port of the buffer channel (11) on a side of the liquid inlet (12); The first screw plug (21) comprises a fixing portion (212) connected to the first screw plug tail portion (211), the fixing portion (212) being located on a side of the first screw plug tail portion (211) away from the valve seat (22), the diameter of the fixing portion (212) being larger than the diameter of the first screw plug tail portion (211), the fixing portion (212) and the first screw plug tail portion (211) being both located in the fourth through hole (114), and the diameter of the fixing portion (212) being adapted to the diameter of the fourth through hole (114); The first screw plug (21), the valve seat (22) and the buffer channel (11) enclose a liquid inlet space (115), the liquid inlet port (12) is always connected to the liquid inlet space (115) through the liquid inlet channel (14), and the valve seat (22) is subjected to the thrust of the high-pressure liquid entering the liquid inlet space (115) and has a tendency to move toward the valve core (32).

5. The bidirectional buffer logic control valve for hydraulic support according to claim 2, characterized in that: The tail portion (222) of the valve seat is provided with a liquid passage hole (2221), and the front side surface of the valve core head (321) is a conical surface. When the valve seat (22) contacts the valve core (32), a portion of the valve core head (321) at the conical surface extends into the liquid passage hole (2221), so that the valve seat (22) and the valve core (32) form a hard seal.

6. The bidirectional buffer logic control valve for a hydraulic support according to claim 5, characterized in that: The first screw plug tail (211) is provided with a first groove (2111), the valve seat head (221) is provided with a second groove (2211), and the first spring (23) has two ends respectively abutting against the first groove (2111) and the second groove (2211) to cushion the valve seat (22).

7. The bidirectional buffer logic control valve for a hydraulic support according to claim 6, characterized in that: A liquid passage groove (2212) is provided on the end surface of the valve seat head (221), the liquid passage groove (2212) is in communication with the second groove (2211), and the second groove (2211) is in communication with the liquid passage hole (2221).

8. The bidirectional buffer logic control valve for a hydraulic support according to claim 1, characterized in that: The outer side wall of the valve core head (321) at the fifth through hole (3211) is provided with a cut surface (3212) so that a distance exists between the valve core head (321) at the fifth through hole (3211) and the inner wall of the second through hole (112).

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