A multi-stage support mechanism suitable for large mining height hydraulic support

Abstract

The application provides a multi-stage wall protection mechanism suitable for a large-mining-height hydraulic support, relates to the technical field of underground coal mining support equipment, and comprises: a telescopic assembly arranged on a top beam of the hydraulic support; a plurality of follow-up fitting components capable of swinging and adjusting postures to fit the coal wall according to the concave-convex, fissure, bedding discordance and cutting trace of the surface of the coal wall are arranged at the telescopic end of the telescopic assembly; and a buffer assembly for buffering the telescopic end to maintain the stable support of the follow-up fitting components on the coal wall is arranged in the telescopic assembly. The application has a reasonable structure, can improve the stress uniformity of the wall protection interface, reduce the local stress concentration degree, reduce the crushing effect of the wall protection plate on the surface layer of the coal wall and the instability risk caused by the crushing effect.

Description

Technical Field

[0001] This invention relates to the field of support equipment technology for underground coal mining, specifically to a multi-stage support mechanism suitable for hydraulic supports with high mining heights. Background Technology

[0002] With the increasing demand for efficient mining of thick and extra-thick coal seams, high-extraction fully mechanized mining technology has become an important means for many mines to achieve high production and efficiency. In actual production, the mining height of the working face is constantly increasing, with some mines reaching over 6 meters in fully mechanized working face height. While increasing the mining height improves resource recovery efficiency, it also significantly amplifies the exposed height of the coal face, making coal face stability issues more prominent. Especially during periods of periodic pressure, intensified roof activity, and redistribution of mining-induced stress, tall coal faces are more prone to spalling, rockfalls, and even local instability, thereby threatening personnel safety, equipment operation, and working face advancement efficiency.

[0003] In the existing technology, there is a complex support environment characterized by large coal wall exposure height, significant differences in deformation patterns along the height direction, rough and irregular coal wall surface morphology, obvious effects of periodic pressure or mining disturbance, possible alternation of local bulging and spalling, and the need for the support device to have both large coverage capacity and to avoid excessively rigid forced pressure on the coal wall. Under such working conditions, although traditional two-stage rigid sidewalls can achieve basic forward extension and side blocking, their sidewall interface is usually a rigid plane and mainly relies on hydraulic cylinders to provide pressure. The hydraulically locked rigid sidewalls can only resist coal wall deformation in a "hard contact" manner. When the coal wall is deformed and unstable, it does not always show a slow and continuous outward bulging. Instead, it often shows a short-term rapid bulging, local collapse, or impact-type block falling during the periodic pressure, roof activity enhancement, or stress redistribution stages. Once the coal wall suddenly bulges towards the support, the sidewalls lack the necessary flexible retreat and initial buffering capacity. The impact energy will be concentrated on the surface of the coal body, causing the surface coal body, which was originally able to maintain its integrity, to be crushed. Once the surface coal body is crushed, it is easy for it to continue to break and fall along the crushed area, causing the crushed area to gradually increase and eventually transform into a larger-scale spalling expansion.

[0004] Moreover, the actual coal face in underground coal mines is usually not an ideal flat plane, but is often accompanied by discontinuous surface features such as cutting steps, local protrusions, pits, cracks, intercalation of rock, and stratification faults. For this type of coal face, conventional rigid side panels are difficult to achieve surface contact after being pressed against. The actual effective stress area is usually concentrated in a few protruding points, causing a sharp increase in local contact pressure. After the pressed part breaks first, a new gap is formed between the side panel and the coal face, and the supporting force is transformed into an inducement for the coal to bulge outward. The original support effect is difficult to maintain continuously, and often only local point contact or line contact can be formed. It is difficult to establish continuous, uniform, and stable lateral constraints, and it is easy for local stress concentration to cause hard pressure between the traditional rigid side panel and the coal face, crushing the surface of the coal face and inducing or amplifying the instability of the coal face. There is an urgent need for a multi-stage side panel support mechanism suitable for hydraulic supports with large mining height to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a multi-stage side protection mechanism suitable for hydraulic supports with high mining heights, thereby solving the problems mentioned in the background art. The present invention has a reasonable structure, which can improve the uniformity of stress on the side protection interface, reduce the degree of local stress concentration, reduce the crushing effect of the side protection plate on the coal wall surface, and reduce the risk of side collapse caused by it.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage support mechanism suitable for hydraulic supports with high mining heights, comprising:

[0007] Telescopic assembly installed on the top beam of the hydraulic support;

[0008] The telescopic end of the telescopic component is equipped with multiple follow-fitting components that can swing and adjust their posture according to the unevenness, cracks, stratification faults and cutting marks on the coal wall surface to fit the coal wall.

[0009] The telescopic component is internally equipped with a buffer component for buffering the telescopic end to maintain the stable support of the coal wall by the follow-up fitting component.

[0010] Furthermore, the telescopic assembly includes a primary sleeve disposed on the top beam of the hydraulic support, a hydraulic cylinder disposed inside the primary sleeve, a secondary sleeve disposed at the end of the telescopic shaft of the hydraulic cylinder, the secondary sleeve being slidably sleeved inside the primary sleeve and having its end protruding outward, and a tertiary sleeve being slidably disposed inside the secondary sleeve, the end of the tertiary sleeve being able to extend outward from the outside of the secondary sleeve.

[0011] The follow-up bonding component is disposed on the side wall of the third-stage sleeve away from the second-stage sleeve.

[0012] Furthermore, the secondary sleeve includes a cylinder disposed inside the primary sleeve, one end of the cylinder is provided with a cover plate located inside the primary sleeve, and a mounting bolt is provided between the cover plate and the cylinder;

[0013] The cover plate is connected to the telescopic shaft of the hydraulic cylinder.

[0014] Furthermore, the third-stage sleeve includes a guide plate disposed inside the second-stage sleeve, and a protruding plate extending through the end of the cylinder is disposed on the side of the guide plate away from the hydraulic cylinder, and a support plate is disposed on the side of the protruding plate away from the guide plate;

[0015] The follow-up bonding component is disposed on the side wall of the support plate away from the protruding plate.

[0016] Furthermore, the buffer assembly includes a primary buffer element disposed inside the secondary sleeve;

[0017] The primary buffer assembly includes a disc spring disposed inside the secondary sleeve. One end of the disc spring is connected to one end of the inner wall of the secondary sleeve, and the other end of the disc spring is connected to one end of the tertiary sleeve.

[0018] Furthermore, the follow-up bonding assembly includes a plurality of connecting seats disposed on the side wall of the third-stage sleeve away from the second-stage sleeve, each connecting seat being provided with a ball hinge, each ball hinge being provided with a connecting seat, and each connecting seat being provided with a bonding plate.

[0019] Furthermore, the buffer assembly also includes a secondary buffer component disposed on the primary sleeve;

[0020] The secondary buffer includes an oil tank located at the bottom of the primary sleeve. A two-way overflow valve is provided on the side wall of the oil tank. The input end of the two-way overflow valve is connected to the oil chamber of the hydraulic cylinder through a pipeline. A drain valve is provided on the side wall of the oil tank above the two-way overflow valve.

[0021] Beneficial effects:

[0022] This invention utilizes multiple follower-fitting components that can adjust their posture to fit the coal wall according to the unevenness, cracks, stratification faults, and cutting marks on the coal wall surface. It divides the existing rigid plane into multiple planes formed by these follower-fitting components that contact the coal wall, creating multiple relatively independent yet shared contact surfaces. These surfaces can contact a few protruding points where the actual effective stress area is concentrated, achieving multi-faceted dispersed contact and improving stress uniformity. Combined with a buffer component, the buffer component cushions the follower-fitting components, preventing a sharp increase in local contact pressure that could lead to the crushed area breaking first, creating new gaps between the support plate and the coal wall, and causing the supporting force to transform into a factor that induces coal bulging. This facilitates maintaining the original support function, reduces the degree of local stress concentration, and minimizes the crushing effect of the support plate on the coal wall surface and the resulting risk of spalling and instability.

[0023] The buffer component buffers the follow-up bonding component, providing necessary flexibility and initial buffering capacity to prevent impact energy from being concentrated on the coal surface, thus preventing the surface coal from being crushed, reducing the crushing range, and preventing the expansion of spalling.

[0024] When the coal wall bulges towards the hydraulic support beam due to periodic pressure or local instability, the third-stage sleeve can retract to a limited extent along the internal guide structure of the second-stage sleeve. The stress-bearing part at the rear end of the third-stage sleeve pushes the disc spring in the first-stage buffer to compress, so that the initial impact of high frequency and small displacement is first absorbed by the elastic unit. This force path avoids the direct rigid transmission of reverse load to the hydraulic cylinder, thus improving the defects of rigid compression and peak stress concentration in traditional side protection mechanisms from a structural principle perspective. As the load continues to increase, the pressure in the pressurized oil chamber of the hydraulic cylinder increases synchronously. The pressure is transmitted to the bidirectional relief valve through the pipeline. In order to protect the hydraulic cylinder, when the pressure reaches a certain level... After the preset threshold is reached, the two-way relief valve opens, and the hydraulic oil in the pressurized oil chamber of hydraulic cylinder 8 enters the oil tank, reducing the oil pressure in the oil chamber of the hydraulic cylinder. This causes the hydraulic cylinder to retract in a controlled manner, and the secondary sleeve, tertiary sleeve and follow-up fitting components thus obtain further yielding displacement and maintain relatively stable support resistance during the yielding process. This two-stage yielding mechanism, composed of disc springs and two-way relief valves, ensures that the mechanism will not lose its support function when dealing with sudden bulging of the coal wall, nor will it crush the surface of the coal wall due to excessive rigid top pressure. This avoids the hard top pressure between the traditional rigid side plate and the coal wall, which can induce surface crushing and side instability. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of a multi-stage support mechanism for hydraulic supports with high mining height according to an embodiment of the present invention.

[0027] Figure 2 This is a front sectional view of a multi-stage support mechanism for a hydraulic support with high mining height according to an embodiment of the present invention.

[0028] Figure 3 This is a front sectional view of the connection between the secondary and tertiary sleeves in a multi-stage support mechanism for a hydraulic support with high mining height, according to an embodiment of the present invention.

[0029] Figure 4 This is a right sectional view of the connection between the primary sleeve and the buffer assembly in a multi-stage support mechanism for a high-extraction hydraulic support according to an embodiment of the present invention.

[0030] Figure 5 This is a perspective view of the connection between a portion of the ball joint and the bonding plate in a follower bonding assembly of a multi-stage support mechanism for a high-extraction hydraulic support according to an embodiment of the present invention.

[0031] The components include: 1. Hydraulic support top beam; 2. Primary sleeve; 3. Secondary sleeve; 31. Cover plate; 32. Mounting bolt; 33. Cylinder body; 4. Tertiary sleeve; 41. Guide plate; 42. Extension plate; 43. Support plate; 5. Follow-up fitting assembly; 51. Connecting seat; 52. Ball hinge; 53. Fitting plate; 531. Connecting seat; 6. Buffer assembly; 61. Primary buffer component; 62. Secondary buffer component; 621. Pipeline; 622. Two-way relief valve; 623. Oil tank; 624. Drain valve; 7. Telescopic assembly; 8. Hydraulic cylinder.

[0032] The accompanying drawings are provided to further understand the embodiments and form part of the specification. They are used together with the embodiments for explanation and do not constitute a limitation on the embodiments. Detailed Implementation

[0033] The technical solutions in 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. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection.

[0034] In the description of the embodiments, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments.

[0035] like Figure 1 As shown, this embodiment of the invention provides a multi-stage support mechanism suitable for hydraulic supports with high mining heights, comprising:

[0036] Telescopic assembly 7 is installed on the top beam 1 of the hydraulic support;

[0037] The telescopic end of the telescopic component 7 is equipped with multiple follow-up fitting components 5 that can swing and adjust their posture according to the unevenness, cracks, stratification faults and cutting marks on the coal wall surface to fit the coal wall.

[0038] The telescopic component 7 is internally equipped with a buffer component 6 for buffering the telescopic end to maintain the stable support of the coal wall by the follow-up fitting component 5. This design utilizes multiple moving contact components 5, which can adjust their posture to conform to the coal wall surface based on its irregularities, cracks, bedding faults, and cutting marks. The existing rigid plane is divided into multiple planes formed by these moving contact components 5, creating multiple relatively independent yet shared contact surfaces. These surfaces can contact a few protruding points within the effective stress area, achieving multi-faceted, dispersed contact and improving stress uniformity. Combined with a buffer component 6, the buffer component 6 cushions the moving contact components 5, preventing a sudden increase in local contact pressure that could lead to premature breakage of the crushed area. This would create new gaps between the support plate and the coal wall, transforming the supporting force into a factor that causes coal bulging. This design maintains the original support function, reduces local stress concentration, minimizes the crushing effect of the support plate on the coal wall surface, and reduces the risk of spalling instability. The buffer component 6 provides necessary flexibility and initial buffering capacity, preventing concentrated impact energy on the coal surface, avoiding crushing of the surface coal, reducing the fracture range, and preventing spalling expansion.

[0039] Reference Figure 1 and Figure 2 The telescopic assembly 7 includes a primary sleeve 2 installed on the top beam 1 of the hydraulic support. A hydraulic cylinder 8 is installed inside the primary sleeve 2. A secondary sleeve 3 is installed at the end of the telescopic shaft of the hydraulic cylinder 8. The secondary sleeve 3 is slidably sleeved inside the primary sleeve 2 and its end can extend outward. A tertiary sleeve 4 is slidably installed inside the secondary sleeve 3. The end of the tertiary sleeve 4 can extend outward from the secondary sleeve 3.

[0040] The follower-fitting component 5 is installed on the side wall of the tertiary sleeve 4 away from the secondary sleeve 3. This design uses the operation of the hydraulic cylinder 8 to drive the secondary sleeve 3 to extend along the inner wall of the primary sleeve 2. The movement of the secondary sleeve 3 causes the tertiary sleeve 4 to move towards the side closer to the coal wall. The movement of the tertiary sleeve 4 causes the follower-fitting component 5 on it to fit against the coal wall, forming a multi-stage deployment support structure suitable for coal walls with high mining height.

[0041] Reference Figure 2 and Figure 3The secondary sleeve 3 includes a cylinder 33 disposed inside the primary sleeve 2. One end of the cylinder 33 is provided with a cover plate 31 located inside the primary sleeve 2. An installation bolt 32 is provided between the cover plate 31 and the cylinder 33.

[0042] The cover plate 31 is connected to the telescopic shaft of the hydraulic cylinder 8. This design facilitates the installation of the third-stage sleeve 4 and the connection between the hydraulic cylinder 8 and the second-stage sleeve 3.

[0043] Reference Figure 3 The third-stage sleeve 4 includes a guide plate 41 disposed inside the second-stage sleeve 3. The guide plate 41 is provided with an extension plate 42 that penetrates the end of the cylinder 33 on the side away from the hydraulic cylinder 8. The extension plate 42 is provided with a support plate 43 on the side away from the guide plate 41.

[0044] The follow-up bonding component 5 is disposed on the side wall of the support plate 43 away from the protruding plate 42. This design improves the stability of the lateral movement of the protruding plate 42 through the guide plate 41, and provides stable support for the follow-up bonding component 5 through the support plate 43; wherein, the guide plate 41 on the third-stage sleeve 4 is conveniently placed inside the second-stage sleeve 3 through the cover plate 31, the cylinder 33 and the mounting bolts 32.

[0045] Reference Figure 2 and Figure 3 The buffer assembly 6 includes a primary buffer 61 disposed inside the secondary sleeve 3;

[0046] The primary buffer assembly 6 includes a disc spring disposed inside the secondary sleeve 3. One end of the disc spring is connected to one end of the inner wall of the secondary sleeve 3, and the other end of the disc spring is connected to one end of the tertiary sleeve 4. This design uses a disc spring in the primary buffer 61 to buffer the tertiary sleeve 4, and then the follower-fitting component 5. When the coal wall suddenly bulges, the tertiary sleeve 4 can first generate a limited retraction displacement relative to the secondary sleeve 3. The impact peak is absorbed and reduced by the disc spring. From a structural principle perspective, this design improves the defects of traditional side protection mechanisms, such as rigid compression and peak stress concentration. It also protects the hydraulic cylinder 8 and avoids the phenomenon that a sudden increase in local contact pressure leads to the crushed part breaking first, and the formation of a new gap between the side protection plate and the coal wall, which transforms the supporting force into an inducement for the coal wall to bulge outward. This facilitates the maintenance of the original support function, reduces the degree of local stress concentration, reduces the crushing effect of the side protection plate on the coal wall surface, and reduces the risk of side collapse caused by this. One end of the disc spring is connected to the cover plate 31 in the secondary sleeve 3 and the disc spring is located inside the secondary sleeve 3. The other end of the disc spring is connected to the guide plate 41 in the tertiary sleeve 4, which facilitates the buffering of the follower-fitting component 5 on the tertiary sleeve 4.

[0047] Reference Figure 2 and Figure 5The follow-up bonding component 5 includes multiple connecting seats 51 disposed on the side wall of the third-stage sleeve 4 away from the second-stage sleeve 3. Each connecting seat 51 is provided with a ball hinge 52, each ball hinge 52 is provided with a connecting seat 531, and each connecting seat 531 is provided with a bonding plate 53. This design ensures that the bonding plate 53 can swing and adjust its posture to fit the coal wall according to the unevenness, cracks, stratification faults, and cutting marks on the coal wall surface. The existing rigid plane is divided into multiple follow-up bonding surfaces that contact the coal wall, forming multiple relatively independent but jointly stressed contact surfaces. When the telescopic component 7 drives the bonding plate 53 to extend forward and press against the coal wall, the bonding plates 53 at different positions can adaptively deflect around their respective ball hinge connection points, so that the bonding interface can conform to the local coal wall. The change in morphology allows the load, which was originally concentrated on a few protrusions, to be redistributed among multiple contact surfaces. It can contact the few protrusions where the actual effective stress area is concentrated, achieving multi-faceted dispersed contact and improving the uniformity of stress distribution. The connecting seat 51 facilitates the connection between the ball hinge 52 and the three-stage sleeve 4. The connecting seat 531 facilitates the connection between the ball hinge 52 and the bonding plate 53. The connecting seat 51 is connected to the support plate 43 in the three-stage sleeve 4. The swing of the ball hinge 52 can better conform to the undulation angle of the coal wall surface.

[0048] Reference Figure 1 , Figure 2 and Figure 4 The buffer assembly 6 also includes a secondary buffer 62 disposed on the primary sleeve 2;

[0049] The secondary buffer 62 includes an oil tank 623 located at the bottom of the primary sleeve 2. A two-way overflow valve 622 is installed on the side wall of the oil tank 623. The input end of the two-way overflow valve 622 is connected to the oil chamber of the hydraulic cylinder 8 via a pipeline 621. A drain valve 624 is located above the two-way overflow valve 622 on the side wall of the oil tank 623. This design, through the secondary buffer 62 in the buffer assembly 6, ensures that the entire mechanism maintains static support when the coal wall is in a relatively stable phase. After entering the periodic pressure phase, the upper and middle parts of the coal wall bulge towards the hydraulic support beam 1. The front-end contact plate 53 automatically adjusts its posture based on the swing freedom of the ball hinge 52, maintaining a relatively close contact level. If the coal wall continues to push outwards, and bulges towards the hydraulic support beam 1 due to periodic pressure or local instability, the tertiary sleeve 4 can generate limited return along the internal guide structure of the secondary sleeve 3. The compression of the rear end of the three-stage sleeve 4 pushes the disc spring in the first-stage buffer 61 to compress, so that the initial impact of high frequency and small displacement is first absorbed by the elastic unit. This force path avoids the direct rigid transmission of reverse load to the hydraulic cylinder 8, and improves the defects of rigid compression and peak stress concentration in traditional side protection mechanisms from the perspective of structural principle. As the load continues to increase, the pressure in the pressurized oil chamber of the hydraulic cylinder 8 increases synchronously. The pressure is transmitted to the bidirectional relief valve 622 through the pipeline 621. In order to protect the hydraulic cylinder 8, the bidirectional relief valve opens when the preset threshold is reached. When valve 622 opens, hydraulic oil in the pressurized oil chamber of hydraulic cylinder 8 enters the oil tank 623, reducing the oil pressure inside hydraulic cylinder 8. This causes hydraulic cylinder 8 to retract in a controlled manner, allowing the secondary sleeve 3, tertiary sleeve 4, and follow-up fitting assembly 5 to achieve further retraction displacement and maintain relatively stable support resistance during the retraction process. This two-stage retraction mechanism, composed of a disc spring and a two-way relief valve 622, ensures that the mechanism neither loses its support function nor crushes the coal wall surface due to excessive rigid pressure when dealing with sudden coal wall bulging. This method avoids the hard pressure between the traditional rigid support plate and the coal wall, which can induce surface crushing and spalling instability. Under field conditions, this working method can significantly reduce the probability of local coal wall fracture, splashing, and spalling expansion, while improving the stability of the working space in front of the support. The support mechanism is no longer simply a rigid pressure on the coal wall, but forms a two-stage load control process of "first mechanical energy absorption, then hydraulic constant resistance yielding". This working method is particularly suitable for complex mine pressure environments with strong periodic pressure, obvious local bulging, and coexistence of dynamic load impact and static load extrusion.

[0050] This invention is particularly suitable for coal wall protection processes in soft coal, jointed coal, coal with developed bedding, coal with interbedded gangue, and coal walls with obvious loosening in the middle and upper parts. In these types of coal bodies, the coal wall does not necessarily bulge outward as a whole after being stressed. In more cases, it manifests as localized peeling of the surface layer, sheet-like detachment after the cracks are connected, displacement of interbedded gangue, or crushing of weak interlayers first. If conventional side protection plates continuously press against the coal wall with high local pressure, they will often accelerate the crushing and separation of weak parts, causing the original local loosening to evolve into a larger area of ​​sheeting. The front-end moving bonding plate 53 array of this invention can disperse the support pressure with multiple relatively independent contact surfaces. The disc spring in the primary buffer 61 can preferentially absorb the initial impact and avoid the instantaneous rigid peak load being directly applied to the coal surface. The bidirectional overflow valve 622 in the secondary buffer 62 can provide controlled retreat under subsequent continuous compression, so that the side protection effect is closer to "constrained flexible restraint" rather than "rigid top pressure failure". Therefore, the present invention is particularly suitable for weak coal walls and heterogeneous coal wall environments where strong rigid surface pressure is not suitable for lateral support. In such scenarios, it can better demonstrate its substantial progress compared with traditional side support technology. Among them, the drain valve 624 replenishes or drains the hydraulic oil inside the oil tank 623 as needed.

[0051] Reference Figures 1-5 As an embodiment of the present invention: when it is necessary to protect the coal wall, the hydraulic cylinder 8 drives the secondary sleeve 3 to extend along the inner wall of the primary sleeve 2. The movement of the secondary sleeve 3 drives the tertiary sleeve 4 to move towards the side closer to the coal wall. The movement of the tertiary sleeve 4 drives the follow-up fitting component 5 on it to fit with the coal wall, forming a multi-stage unfolding support structure suitable for coal walls with high mining height, and performing protective operation on the coal wall.

[0052] When the coal wall is in a relatively stable stage, the entire structure maintains static support. After entering the periodic pressure stage, the upper and middle coal wall bulges out towards the hydraulic support top beam 1. The front-end bonding plate 53 will automatically adjust its posture by relying on the swing freedom of the ball hinge 52. The ball hinge 52 in the multiple follower bonding components 5 ensures that the bonding plate 53 can swing and adjust its posture to fit the coal wall according to the unevenness, cracks, stratification faults and cutting marks on the coal wall surface, forming multiple relatively independent but jointly stressed contact surfaces. This allows the bonding interface to adapt to the changes in the local morphology of the coal wall. The load that was originally concentrated on a few protrusions can be redistributed among multiple contact surfaces, and can contact the few protrusions where the actual effective stress area is concentrated, achieving multi-faceted dispersed contact and improving the uniformity of stress.

[0053] As the coal wall continues to push outward, and bulges towards the hydraulic support beam 1 due to periodic pressure or local instability, the third-stage sleeve 4 can retract to a limited extent along the internal guide structure of the second-stage sleeve 3. The force-bearing part at the rear end of the third-stage sleeve 4 pushes the disc spring in the first-stage buffer 61 to compress, so that the initial impact of high frequency and small displacement is first absorbed by the elastic unit. This force path avoids the direct rigid transmission of reverse load to the hydraulic cylinder 8. From a structural principle perspective, it improves the defects of rigid compression and peak stress concentration in traditional side protection mechanisms, protects the hydraulic cylinder 8, and avoids the phenomenon that a sudden increase in local contact pressure leads to the crushed part breaking first, and the formation of a new gap between the side protection plate and the coal wall, which transforms the supporting force into an inducement for the coal wall to bulge outward. This facilitates the maintenance of the original support function, reduces the degree of local stress concentration, reduces the crushing effect of the side protection plate on the surface of the coal wall, and reduces the risk of side collapse and instability caused by it.

[0054] As the load continues to increase, the pressure in the pressurized oil chamber of hydraulic cylinder 8 increases synchronously. The pressure is transmitted to the bidirectional relief valve 622 through pipeline 621. In order to protect hydraulic cylinder 8, when the preset threshold is reached, the bidirectional relief valve 622 opens, and the hydraulic oil in the pressurized oil chamber of hydraulic cylinder 8 enters the oil tank 623, reducing the oil pressure in the oil chamber of hydraulic cylinder 8. Hydraulic cylinder 8 retracts in a controlled manner, and the secondary sleeve 3, tertiary sleeve 4 and follow-up fitting component 5 obtain further yielding displacement and maintain relatively stable support resistance during the yielding process. This two-stage yielding mechanism, which is composed of disc spring and bidirectional relief valve 622, ensures that the mechanism will not lose its support function when dealing with sudden bulging of the coal wall, nor will it crush the surface of the coal wall due to excessive rigid top pressure. It avoids the hard top pressure between the traditional rigid side plate and the coal wall, which would induce surface crushing and side instability.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0056] The embodiments have been described above, and such description is not restrictive. The figures shown are only one embodiment, and the actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit, such design should fall within the scope of protection.

Claims

1. A multi-stage support mechanism suitable for hydraulic supports with high extraction height, comprising: Telescopic assembly (7) installed on the top beam (1) of the hydraulic support; Its features are: The telescopic component (7) is provided with multiple follow-up fitting components (5) that can swing and adjust their posture according to the unevenness, cracks, stratification faults and cutting marks on the coal wall surface to fit the coal wall. The telescopic component (7) is provided with a buffer component (6) for buffering the telescopic end to maintain the stable support of the coal wall by the follow-up fitting component (5).

2. The multi-stage support mechanism for hydraulic supports with high mining height as described in claim 1, characterized in that, The telescopic assembly (7) includes a first-stage sleeve (2) disposed on the top beam (1) of the hydraulic support. A hydraulic cylinder (8) is disposed inside the first-stage sleeve (2). A second-stage sleeve (3) is disposed at the end of the telescopic shaft of the hydraulic cylinder (8). The second-stage sleeve (3) is slidably sleeved inside the first-stage sleeve (2) and its end can extend outward. A third-stage sleeve (4) is slidably disposed inside the second-stage sleeve (3). The end of the third-stage sleeve (4) can extend outward from the second-stage sleeve (3). The follow-up bonding component (5) is disposed on the side wall of the third-stage sleeve (4) away from the second-stage sleeve (3).

3. The multi-stage support mechanism for hydraulic supports with high mining height as described in claim 2, characterized in that, The secondary sleeve (3) includes a cylinder (33) disposed inside the primary sleeve (2), and a cover plate (31) located inside the primary sleeve (2) is provided at one end of the cylinder (33), and an installation bolt (32) is provided between the cover plate (31) and the cylinder (33). The cover plate (31) is connected to the telescopic shaft of the hydraulic cylinder (8).

4. The multi-stage support mechanism for hydraulic supports with high mining heights according to claim 3, characterized in that, The third-stage sleeve (4) includes a guide plate (41) disposed inside the second-stage sleeve (3). The guide plate (41) is provided with an extension plate (42) that penetrates the end of the cylinder (33) on the side away from the hydraulic cylinder (8). The extension plate (42) is provided with a support plate (43) on the side away from the guide plate (41). The follow-up bonding component (5) is disposed on the side wall of the support plate (43) away from the protruding plate (42).

5. The multi-stage support mechanism for hydraulic supports with high mining height as described in claim 2, characterized in that, The buffer assembly (6) includes a primary buffer (61) disposed inside the secondary sleeve (3). The primary buffer assembly (6) includes a disc spring disposed inside the secondary sleeve (3), one end of which is connected to one end of the inner wall of the secondary sleeve (3), and the other end of which is connected to one end of the tertiary sleeve (4).

6. The multi-stage support mechanism for hydraulic supports with high mining height as described in claim 2, characterized in that, The follow-up bonding component (5) includes a plurality of connecting seats (51) disposed on the side wall of the third sleeve (4) away from the second sleeve (3). Each connecting seat (51) is provided with a ball hinge (52), each ball hinge (52) is provided with a connecting seat (531), and each connecting seat (531) is provided with a bonding plate (53).

7. The multi-stage support mechanism for hydraulic supports with high mining heights according to claim 5, characterized in that, The buffer assembly (6) also includes a secondary buffer (62) disposed on the primary sleeve (2). The secondary buffer (62) includes an oil tank (623) located at the bottom of the primary sleeve (2). A two-way overflow valve (622) is provided on the side wall of the oil tank (623). The input end of the two-way overflow valve (622) is connected to the oil chamber of the hydraulic cylinder (8) through a pipeline (621). A drain valve (624) located above the two-way overflow valve (622) is provided on the side wall of the oil tank (623).

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