Coal mine hydraulic support anti-impact stand column and multi-stage pressure relief method thereof

Abstract

The invention discloses a coal mine hydraulic support anti-impact stand column and a multi-stage pressure relief method thereof. The anti-impact stand column comprises a movable column, and an inner leakage plane pressure limiting valve is assembled in an inner cavity of the movable column. The inner leakage plane pressure limiting valve comprises a pressure limiting valve piston, a pressure limiting valve element and a first-stage elastic element. A valve seat plate is assembled in an inner cavity of the plunger; a valve port is formed in the middle area of the valve seat plate; the pressure-limiting valve piston is movably assembled in the lower cavity of the plunger, and a plurality of damping holes are formed in the pressure-limiting valve piston in a penetrating manner; the lower end of the pressure-limiting valve element is connected with the pressure-limiting valve piston, and the upper end of the pressure-limiting valve element penetrates through the valve port and can close / open the valve port. The first-stage elastic element is arranged in the circumferential direction of the pressure-limiting valve element, and the two ends of the first-stage elastic element make contact with the valve seat plate and the pressure-limiting valve piston respectively. Therefore, stable pressure relief of strong impact pressure exceeding the set pressure of a conventional safety valve of the stand column can be achieved, the impact resistance of the stand column is improved, and the safety valve is particularly suitable for a hydraulic support under high-energy strong impact load.

Description

Technical Field

[0001] This invention relates to an anti-impact column for a hydraulic support in a coal mine and its multi-stage pressure relief method, belonging to the technical field of underground coal mining support equipment. Background Technology

[0002] In recent years, with the continuous increase in the depth and intensity of coal mining in my country, the dynamic disasters such as rock bursts faced by coal mining faces have become increasingly serious. As the core pressure-bearing component of the support system, the hydraulic support column's impact resistance performance is directly related to the safety of the entire coal mining production.

[0003] Current mainstream column shock protection designs include the use of high-flow safety valves, expanded column structures, external accumulators, and additional energy-absorbing components. However, all of these have significant drawbacks: the core design of high-flow safety valves is to increase the pressure relief efficiency by increasing the flow area, but due to the inertia of the valve core movement and the viscous damping of hydraulic oil, there is an unavoidable response lag; both internal expansion of the column and connection of external accumulators rely on the principle of expanding the cavity or storing energy to buffer the impact, but both have structural limitations and reliability shortcomings; additional energy-absorbing components are mostly one-time designs that require frequent replacement, have insufficient impact resistance, and are not economical.

[0004] Based on the above situation, there is an urgent need for a new type of impact-resistant column with multi-stage pressure relief function, which can quickly relieve pressure on the column under high-energy and strong impact load conditions, so as to achieve stable operation and ensure the safe and efficient mining of deep coal resources. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-impact column for a coal mine hydraulic support and its multi-stage pressure relief method. By assembling an internal leakage plane pressure relief valve in the piston, it solves the problems of slow response speed and insufficient pressure relief capacity in the existing hydraulic support column pressure relief method.

[0006] To achieve the above-mentioned technical objectives, the present invention will adopt the following technical solution: An anti-impact column for a coal mine hydraulic support includes an anti-impact column body, the anti-impact column body including a piston, the piston having an inner cavity along its own axial direction, and an internal leakage plane pressure relief valve being assembled in the inner cavity of the piston; the internal leakage plane pressure relief valve includes a pressure relief valve piston, a pressure relief valve core, and a primary elastic element; The piston is fitted with a valve seat plate in its inner cavity, which divides the piston cavity into cavity C and a lower cavity below cavity C. A piston pressure relief port is provided on the side wall of cavity C. A valve port is provided in the middle area of ​​the valve seat plate. The pressure relief valve piston is movably mounted in the lower cavity, and several damping holes are provided through the pressure relief valve piston. The lower end of the pressure relief valve core is connected to the pressure relief valve piston, while the upper end passes through the valve port and can close / open the valve port. The primary elastic element is arranged around the circumference of the pressure relief valve core, and the two ends of the primary elastic element are in contact with the valve seat plate and the pressure relief valve piston, respectively.

[0007] Preferably, a valve core elastic limiting ring is arranged in the cavity C, and the lower end of the valve core elastic limiting ring is directly opposite the upper end of the pressure relief valve core.

[0008] Preferably, a secondary elastic element is arranged in the cavity C; the two ends of the secondary elastic element are respectively in contact with the top of the cavity C and the upper end of the pressure relief valve core.

[0009] Preferably, the impact-resistant column body adopts a double telescopic column structure, and also includes an outer cylinder and a middle cylinder assembled in the outer cylinder and capable of telescopically extending along the inner wall of the outer cylinder; the piston is assembled in the middle cylinder and capable of telescopically extending along the inner wall of the middle cylinder; the bottom of the rodless cavity of the outer cylinder is provided with an outer cylinder pressure relief port, and the inner cavity of the piston is connected to the rodless cavity of the middle cylinder; the rodless cavity of the outer cylinder is connected to the column safety valve through the outer cylinder pressure relief port.

[0010] Preferably, the lower cavity is divided into cavity B and cavity D below cavity B by the pressure relief valve piston; cavity D is directly connected to the rodless cavity of the middle cylinder; the pressure relief valve core is T-shaped, including a vertical section and a horizontal section; the vertical section is located in cavity B, and the lower end of the vertical section is connected to the pressure relief valve piston, while the upper end extends out of the valve port and is connected to the horizontal section located in cavity C; a primary elastic element is sleeved around the periphery of the vertical section, and the lower end of the secondary elastic element is in contact with the horizontal section; the vertical section of the pressure relief valve core is connected to the pressure relief valve piston by a fastening element.

[0011] Preferably, the flow and pressure parameters of the column safety valve are set to the rated working flow and pressure of the anti-impact column body, and the rated flow and pressure of the internal leakage plane pressure relief valve are greater than the rated working flow and pressure of the column safety valve.

[0012] Another technical objective of this invention is to provide a multi-stage pressure relief method for the anti-impact column of a hydraulic support, including a pressure relief process for the anti-impact column under normal working pressure and a multi-stage pressure relief process for the anti-impact column under high-energy strong impact load, wherein: The pressure relief process of the anti-impact column under normal working pressure includes: when the roof of the coal mining face is periodically pressurized, the column safety valve is first opened to relieve the pressure on the anti-impact column body until the pressure of the anti-impact column body is lower than the set pressure of the column safety valve, and then the column safety valve is closed. Multi-stage pressure relief process of anti-impact column under high-energy strong impact load: When strong mine pressure or rock burst occurs on the roof of the coal mining face, the safety valve of the column is opened first to relieve pressure on the anti-impact column body. When the internal pressure of the impact column body continues to rise, it pushes the piston of the middle cylinder to retract, causing the emulsion in the rodless chamber of the middle cylinder and chamber D to compress and store energy, thus converting it into high-energy emulsion. When the internal pressure of the impact column body continues to rise, the high-energy emulsion flows into chamber B through the damping holes of the pressure relief valve piston. During this process, if the internal pressure of the impact column body continues to rise and reaches the set pressure of the internal pressure relief valve, the high-energy emulsion pushes the pressure relief valve piston and the pressure relief valve core to move upward. The pressure relief valve core moves upward and opens the valve port of the internal pressure relief valve. The high-pressure emulsion enters chamber C through the valve port of the internal pressure relief valve and is discharged from the piston through the pressure relief port, thus unloading the column. As the pressure in cavity B continues to increase, the opening between the pressure relief valve core and the valve port widens, deforming the elastic limiting ring of the pressure relief valve core, increasing the displacement of the pressure relief valve core, and increasing the opening area of ​​the valve port of the internal leakage plane pressure relief valve. The high-pressure emulsion is discharged in large quantities through the internal leakage plane pressure relief valve and the column safety valve, realizing rapid pressure relief of the anti-impact column body until the pressure of the anti-impact column body is lower than the set pressure of the internal leakage plane pressure relief valve. The plane pressure relief valve is quickly closed by the action of the two elastic elements, realizing staged pressure relief of the column.

[0013] Based on the above-mentioned technical objectives, the present invention has the following advantages compared with the prior art: 1. The hydraulic support anti-impact column provided by this invention incorporates an internally venting planar pressure-limiting valve within the piston rod. On one hand, this valve has a large flow area and employs a planar valve structure, which, compared to existing safety valves externally connected to the outer cylinder, improves response speed and increases the column's pressure relief capacity. On the other hand, the internally venting planar pressure-limiting valve is located inside the piston rod, not occupying the effective extension / retraction stroke of the hydraulic support, thus not affecting the extension / retraction ratio of the hydraulic support.

[0014] 2. The hydraulic support anti-impact column provided by this invention can not only relieve normal working pressure through a conventional column safety valve, but also construct a multi-stage pressure relief method through the primary elastic element, secondary elastic element, and valve core elastic limit ring in the internal leakage plane pressure relief valve, achieving high-energy load impact pressure relief during strong periodic pressure or impact ground pressure. The opening pressure and flow rate of the internal leakage plane pressure relief valve are both greater than those of the external safety valve.

[0015] 3. The internal and external pressure limiting and pressure relief circuits of the impact-resistant column of the present invention improve the hydraulic support column's ability to resist strong impacts, and are particularly suitable for hydraulic supports on working faces under high-energy and strong impact loads. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the anti-impact column of the coal mine hydraulic support described in this invention; Figure 2 This is a flowchart of the multi-stage pressure relief method for the anti-impact column of the coal mine hydraulic support described in this invention; In the diagram: 1-Outer cylinder; 101-Outer cylinder pressure relief port; 102-Outer cylinder liquid inlet; 2-Intermediate cylinder barrel; 201-Intermediate cylinder barrel inlet; 3-Positive piston; 301-Valve seat plate; 302-Positive piston pressure relief port; 4-Internal leakage planar pressure relief valve; 401-Pressure relief valve piston; 402-Damping orifice; 403-Fastening element; 404-Primary elastic element; 405-Pressure relief valve core; 406-Secondary elastic element; 407-Valve core elastic limit ring; 5-Column safety valve. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0018] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used here to describe the spatial positional relationship of a device or feature as shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figure. For example, if the device in the figure is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0019] like Figure 1As shown, the anti-impact column of the coal mine hydraulic support of the present invention includes an anti-impact column body. The anti-impact column body can adopt a single telescopic column structure or a multi-stage telescopic column structure. The attached figure shows a double telescopic column structure, including an outer cylinder 1, a middle cylinder 2 assembled in the outer cylinder 1 and capable of telescopically extending along the inner wall of the outer cylinder 1, and a piston 3 assembled in the middle cylinder 2 and capable of telescopically extending along the inner wall of the middle cylinder 2. The rodless cavity of the outer cylinder 1 is provided with an outer cylinder pressure relief port 101, and a column safety valve 5 is connected through the outer cylinder pressure relief port 101. The piston 3 has an inner cavity arranged along its own axial direction. An internal relief plane pressure relief valve 4 is installed in the inner cavity of the piston 3, and the inner cavity of the piston 3 communicates with the rodless cavity of the middle cylinder 2. The flow and pressure parameters of the column safety valve 5 are set to the rated working flow and pressure of the double telescopic anti-impact column. The rated flow and pressure of the internal leakage plane pressure relief valve 4 are greater than the rated working flow and pressure of the column safety valve 5. These parameters are determined by the magnitude of the impact load and the dimensions of the anti-impact column body.

[0020] To facilitate the installation of the internal pressure relief valve 4, a valve seat plate 301 is fitted inside the piston 3. The valve seat plate 301 divides the piston into cavity C and a lower cavity below cavity C. The lower cavity is further divided into cavity B and cavity D below cavity B by the pressure relief valve piston 401. Cavity D is directly connected to the rodless cavity of the middle cylinder 2. A piston pressure relief port 302 is provided on the side wall of cavity C, and the return fluid pipeline is connected through the piston pressure relief port 302. A valve port is provided in the middle area of ​​the valve seat plate 301.

[0021] The internal leakage planar pressure relief valve 4 includes a pressure relief valve piston 401, a pressure relief valve core 405, and a primary elastic element 404. Specifically: the pressure relief valve piston 401 is movably mounted in the lower cavity, and several damping holes 402 are provided through the piston 401. The lower end of the pressure relief valve core 405 is connected to the pressure relief valve piston 401, while the upper end passes through the valve port and can close / open the valve port; the primary elastic element 404 is arranged circumferentially around the pressure relief valve core 405, and both ends of the primary elastic element 404 are in contact with the valve seat plate 301 and the pressure relief valve piston 401, respectively.

[0022] In the anti-impact column body of the present invention, a valve core elastic limiting ring 407 is arranged in the cavity C, and the lower end of the valve core elastic limiting ring 407 is directly opposite the upper end of the pressure limiting valve core 405, so as to limit the movement range of the pressure limiting valve core 405.

[0023] The impact-resistant column body of the present invention also includes a secondary elastic element 406; the secondary elastic element 406 is sleeved around the elastic limiting ring 407 of the valve core, and both ends of the secondary elastic element 406 are respectively engaged with the top of the cavity C and the upper end of the pressure limiting valve core 405. This causes the pressure limiting valve core 405 to close the valve port of the valve seat plate 301, thereby closing the cavity C and the lower cavity, preventing high-pressure emulsion from entering the cavity C from the lower cavity during normal operation of the impact-resistant column body. Of course, the secondary elastic element 406 can also be disposed inside the elastic limiting ring 407 of the valve core.

[0024] In this invention, the pressure relief valve core 405 is T-shaped, including a vertical section and a horizontal section. The vertical section is located in cavity B, and its lower end is connected to the pressure relief valve piston 401, while its upper end extends out of the valve port and connects to the horizontal section located in cavity C. The vertical section of the pressure relief valve core 405 is connected to the pressure relief valve piston 401 via a fastening element 403. A primary elastic element 404 is sleeved around the periphery of the vertical section, and the lower end of a secondary elastic element 406 is fastened to the horizontal section.

[0025] The hydraulic support anti-impact column proposed in this invention, combined with the column safety valve 5 connected to the outer cylinder, can achieve staged pressure relief of the column under impact pressure. The principle is as follows: The cavity A of the outer cylinder 1 is connected to the column safety valve 5 (the column safety valve 5 is externally mounted on the anti-impact column body) through the outer cylinder pressure relief port 101. The flow and pressure parameters of the column safety valve 5 are set to the rated unloading working flow and working pressure of the anti-impact column body. The rated flow and pressure parameters of the internal leakage plane pressure relief valve 4 are greater than those of the column safety valve, and are determined by the magnitude of the impact load and the size of the column.

[0026] The graded pressure relief method is determined based on the actual load-bearing capacity of the impact-resistant column body.

[0027] When the roof of the coal face experiences periodic pressure, the emulsion in cavity A of the outer cylinder 1 is compressed, absorbing some energy. As the pressure increases, it first reaches the set pressure of the column safety valve 5, which then opens to release pressure. This continues until the pressure of the anti-impact column body falls below the set pressure of the column safety valve 5, at which point the safety valve closes. At this point, the pressure relief of the middle cylinder 2 and piston 3 decreases until the pressure of the entire anti-impact column system stabilizes. When strong mine pressure or rock burst occurs on the roof of the coal mining face, the safety valve 5 of the support column opens first to relieve pressure. However, due to insufficient pressure relief capacity, the internal pressure of the anti-impact support column body continues to rise. The emulsion in the rodless chamber of the middle cylinder 2 and the chamber D of the piston column 3 is compressed under pressure, absorbing some energy and converting into high-energy emulsion. As the pressure increases, the high-energy emulsion squeezes the piston 401 of the planar pressure relief valve and enters the chamber B of the piston column through the damping hole 402. When the pressure set by the internal leakage planar pressure relief valve 4 is reached, the first-stage elastic element 404 is compressed under pressure. At this time, the valve core 405 of the pressure relief valve moves upward under pressure, the second-stage elastic element 406 is compressed under pressure, the valve core 405 of the pressure relief valve opens, and the high-energy emulsion is discharged from the chamber B of the piston column into the chamber C, and discharged from the piston column pressure relief port 302 to the anti-impact support column body, thus achieving impact pressure relief.

[0028] If the pressure rise in chamber B of the piston column cannot be suppressed after the internal pressure relief valve 4 is opened, the internal pressure relief valve 4 will remain open. The valve core 405 will compress the elastic limiting ring 407 until it deforms, increasing the displacement of the valve core 405 and increasing the opening area of ​​the internal pressure relief valve 4. The high-energy emulsion will be discharged in large quantities through the internal pressure relief valve 4 and the column safety valve 5, achieving rapid pressure relief of the column. Until the pressure of the impact column body is lower than the pressure set by the internal pressure relief valve 4, the pressure relief valve 4 will be quickly closed by the action of the primary elastic element 404 and the secondary elastic element 406, thereby avoiding the frame collapse accident caused by excessive unloading of the impact column body.

[0029] Therefore, by using a multi-stage decompression method, the high-energy impact pressure inside the impact-resistant column body can be significantly reduced, thereby achieving impact resistance for both the impact-resistant column body and the hydraulic support.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydraulic support anti-impact column for coal mines, comprising an anti-impact column body, the anti-impact column body including a piston (3), the piston (3) having an inner cavity along its own axial direction, characterized in that, The inner cavity of the piston (3) is equipped with an internal leakage plane pressure relief valve (4); the internal leakage plane pressure relief valve (4) includes a pressure relief valve piston (401), a pressure relief valve core (405), and a first-stage elastic element (404). The inner cavity of the piston (3) is fitted with a valve seat plate (301), and the inner cavity of the piston is divided into cavity C and a lower cavity below cavity C by the valve seat plate (301); the side wall of cavity C is provided with piston pressure relief port (302); the middle area of ​​valve seat plate (301) is provided with valve port; The pressure relief valve piston (401) is movably mounted in the lower cavity, and a number of damping holes (402) are provided through the pressure relief valve piston (401). The lower end of the pressure relief valve core (405) is connected to the pressure relief valve piston (401), while the upper end passes through the valve port and can close / open the valve port; The primary elastic element (404) is arranged around the circumference of the pressure relief valve core (405), and the two ends of the primary elastic element (404) are in contact with the valve seat plate (301) and the pressure relief valve piston (401), respectively.

2. The anti-impact column of the coal mine hydraulic support according to claim 1, characterized in that, A valve core elastic limiting ring (407) is arranged in cavity C, and the lower end of the valve core elastic limiting ring (407) is directly opposite the upper end of the pressure relief valve core (405).

3. The anti-impact column of the coal mine hydraulic support according to claim 2, characterized in that, A secondary elastic element (406) is arranged in the cavity C; the two ends of the secondary elastic element (406) are respectively in contact with the top of the cavity C and the upper end of the pressure relief valve core (405).

4. The anti-impact column of the coal mine hydraulic support according to claim 1, characterized in that, The anti-impact column body adopts a double telescopic column structure, and also includes an outer cylinder (1) and a middle cylinder (2) assembled in the outer cylinder (1) and capable of telescopic movement along the inner wall of the outer cylinder (1); the piston (3) is assembled in the middle cylinder (2) and capable of telescopic movement along the inner wall of the middle cylinder (2); the bottom of the rodless cavity of the outer cylinder (1) is provided with an outer cylinder pressure relief port (101), and the inner cavity of the piston (3) is connected to the rodless cavity of the middle cylinder (2); the rodless cavity of the outer cylinder (1) is connected to the column safety valve (5) through the outer cylinder pressure relief port (101).

5. The anti-impact column of the coal mine hydraulic support according to claim 4, characterized in that, The lower cavity is divided into cavity B and cavity D below cavity B by the pressure relief valve piston (401); cavity D is directly connected to the rodless cavity of the middle cylinder (2); the pressure relief valve core (405) is T-shaped, including a vertical section and a horizontal section; the vertical section is located in cavity B, and the lower end of the vertical section is connected to the pressure relief valve piston (401), while the upper end extends out of the valve port and is connected to the horizontal section placed in cavity C; the first-stage elastic element (404) is sleeved on the periphery of the vertical section, and the lower end of the second-stage elastic element (406) is in contact with the horizontal section; the vertical section of the pressure relief valve core (405) is connected to the pressure relief valve piston (401) through the fastening element (403).

6. The anti-impact column of the coal mine hydraulic support according to claim 4, characterized in that, The flow and pressure parameters of the column safety valve (5) are set to the rated working flow and pressure of the anti-impact column body, and the rated flow and pressure of the internal leakage plane pressure relief valve (4) are greater than the rated working flow and pressure of the column safety valve (5).

7. A multi-stage pressure relief method for an anti-impact column of a hydraulic support, characterized in that, This includes the decompression process of the impact-resistant column under normal working pressure and the multi-stage decompression process of the impact-resistant column under high-energy, high-impact loads, wherein: The pressure relief process of the anti-impact column under normal working pressure includes: when the roof of the coal mining face is periodically pressurized, the column safety valve (5) is opened first to relieve the pressure on the anti-impact column body until the pressure of the anti-impact column body is lower than the set pressure of the column safety valve (5), and then the column safety valve (5) is closed. Multi-stage pressure relief process of anti-impact column under high energy and strong impact load: When strong mine pressure or rock pressure occurs on the roof of the coal mining face, the safety valve (5) of the column is opened first to relieve pressure on the anti-impact column body. When the internal pressure of the anti-impact column body continues to rise, it pushes the piston of the middle cylinder (2) to retract, causing the rodless chamber of the middle cylinder (2) and the emulsion in the cavity D to compress and store energy, thereby converting into high-energy emulsion; when the internal pressure of the anti-impact column body continues to rise, if the internal pressure of the anti-impact column body reaches the set pressure of the internal leakage plane pressure limiting valve (4), the high-energy emulsion pushes the pressure limiting valve piston (401) and the pressure limiting valve core (405) to move upward, the pressure limiting valve core (405) moves upward to open the valve port of the internal leakage plane pressure limiting valve (4), the high-pressure emulsion enters the C cavity through the valve port of the internal leakage plane pressure limiting valve (4), and is discharged from the piston through the pressure relief port (302), thereby realizing the unloading of the column; As the pressure in cavity B continues to increase, the opening between the pressure relief valve core (405) and the valve port increases, which deforms the elastic limiting ring (407) of the squeeze valve core, increases the displacement of the pressure relief valve core (405), and increases the valve port opening area of ​​the internal leakage plane pressure relief valve (4). The high-pressure emulsion is discharged in large quantities through the internal leakage plane pressure relief valve (4) and the column safety valve (5), realizing rapid pressure relief of the anti-impact column body until the pressure of the anti-impact column body is lower than the set pressure of the internal leakage plane pressure relief valve (4). The plane pressure relief valve (4) is rapidly closed by the action of two elastic elements (404, 406), realizing graded pressure relief of the column.

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