Roof self-adaptive constant-resistance supporting equipment and method for coal-pillar-free mining of coal mine

Abstract

The top plate self-adaptive constant-resistance supporting equipment comprises a supporting frame, the supporting frame is composed of a supporting bottom plate, a supporting top plate and a supporting side plate, and the two ends of the supporting side plate are rotationally connected with the supporting bottom plate and the supporting top plate correspondingly; four multi-stage sleeve type yielding stand columns are arranged between the supporting bottom plate and the supporting top plate and connected to the four corner positions of the supporting bottom plate and the four corner positions of the supporting top plate respectively. The multi-stage casing pipe type yielding stand column and the elastic yielding device are adopted, multi-path pressure relief is achieved, and the overall stability and the bearing capacity of the supporting system are enhanced through self-adaptive attachment of the pressure dividing plate; a spring buffering base is further adopted, a buffering spring achieves yielding through compression deformation, constant and stable supporting resistance is provided for the second-stage sleeve, and therefore self-adaptive buffering and stable supporting of the pressure of the top plate are achieved.

Description

Technical Field

[0001] This invention belongs to the field of coal pillarless mining and roadway surrounding rock control technology, specifically a coal mine pillarless mining roof adaptive constant resistance support equipment and method. Background Technology

[0002] In the field of pillarless coal mining, the core working principle of constant resistance support can be summarized as follows: when the support load reaches the preset working resistance, it adapts to the movement of the surrounding rock through controlled slippage or deformation. During this process, the support structure continuously provides a basically constant supporting force to the surrounding rock, thereby avoiding damage due to excessive stress. Constant resistance support works synergistically with the surrounding rock in a "rigid-flexible" manner, maintaining stable support while allowing moderate deformation of the surrounding rock, ultimately achieving shared load-bearing capacity between the support structure and the surrounding rock.

[0003] In practical applications of pillarless mining in coal mines, although traditional rigid supports possess significant support strength, their pressure-relieving capacity is clearly insufficient. They struggle to effectively absorb and release the energy released during the deformation of the surrounding rock in the roadway, easily leading to stress concentration and subsequent eccentric failure. Furthermore, when roof pressure is rapid and the load increases sharply, existing support equipment often fails to respond in time. Safety valves may fail to open properly to relieve pressure due to their own quality issues or blockage by impurities such as coal dust and rust. This causes a sharp increase in internal pressure in the support, ultimately leading to cylinder expansion, deformation, or even bursting, resulting in a complete loss of support capacity.

[0004] Therefore, it is necessary to provide a roof adaptive constant resistance support device and method for coal mine pillarless mining to solve the problems mentioned in the background art. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a coal mine pillarless excavation equipment with adaptive constant resistance roof support, which includes a support frame, the support frame being composed of a support base plate, a support top plate and a support side plate, the two ends of the support side plate being rotatably connected to the support base plate and the support top plate respectively;

[0006] Four multi-stage sleeve-type pressure-relief columns are provided between the supporting base plate and the supporting top plate, and the four multi-stage sleeve-type pressure-relief columns are respectively connected to the four corners of the supporting base plate and the supporting top plate.

[0007] Furthermore, preferably, the top of the supporting top plate is in contact with the top plate of the tunnel, and the bottom of the supporting bottom plate is in contact with the bottom plate of the tunnel.

[0008] The tops of the four multi-stage sleeve-type pressure-relief columns are rotatably connected to the bottom of the supporting top plate; the bottoms of the four multi-stage sleeve-type pressure-relief columns are each provided with a spherical hinge base, and the bottom of the spherical hinge base is hinged to the top of the supporting bottom plate.

[0009] Furthermore, as a preferred embodiment, the multi-stage sleeve-type pressure relief column includes a primary sleeve fixed above the spherical hinge base, a secondary sleeve coaxially embedded and slidably disposed inside the primary sleeve, and a sealing buffer ring disposed between the upper end of the primary sleeve and the secondary sleeve.

[0010] A hydraulic column is coaxially arranged inside the primary sleeve, and the bottom of the hydraulic column is fixed to the upper end face of the spherical hinge base; an inlet pipe connected to the hydraulic column is vertically arranged on the outside of the primary sleeve; a spring buffer base is coaxially arranged inside the primary sleeve, and one end of the hydraulic column is slidably connected through the spring buffer base; the upper end of the spring buffer base is fixed to the lower end face of the secondary sleeve.

[0011] The secondary sleeve has several elastic pressure relief devices coaxially arranged inside, and the uppermost elastic pressure relief device is provided with a column cap that is slidably connected to the secondary sleeve; a mechanical pressure indicator is installed inside the column cap.

[0012] Furthermore, as a preferred embodiment, the spring buffer base includes a worktable sleeved on the outside of the hydraulic column, the upper part of the worktable being fixed to the lower end face of the secondary sleeve; three evenly distributed support rods are vertically arranged along the circumferential direction below the worktable, and the upper end of each support rod is rotatably connected to the bottom of the worktable.

[0013] A base is coaxially arranged below the workbench and sleeved on the outside of the hydraulic column. A buffer spring is provided between the base and the workbench and is sleeved on the outside of the hydraulic column. A first connecting plate is provided between the base and each of the support rods. One end of the first connecting plate is rotatably connected to the base and the other end of the first connecting plate is rotatably connected to the support rod.

[0014] Furthermore, as a preferred embodiment, the inner wall of the primary casing is uniformly provided with three vertical wedge-shaped grooves along the circumferential direction, and the depth of the wedge-shaped grooves increases from top to bottom; the wedge-shaped grooves are located at the upper end of the primary casing, and the length of the wedge-shaped grooves is half the length of the primary casing; each of the support rods corresponds one-to-one with each of the wedge-shaped grooves, and the spring buffer base moves up and down along the vertical direction of the wedge-shaped grooves.

[0015] Furthermore, as a preferred embodiment, the elastic pressure relief device includes a pressure relief base, the interior of which is a hollow structure; a pressure-bearing block is slidably disposed above the pressure relief base; and a plurality of highly elastic spring sheets are sleeved at the connection between the pressure-bearing block and the pressure relief base.

[0016] The lower end of the pressure relief base is connected to the pressure-bearing block in the adjacent lower elastic pressure relief device;

[0017] The pressure base has three evenly distributed pressure plates vertically arranged along the circumference outside. A second connecting plate is provided between the upper end of the pressure base and the pressure plates. One end of the second connecting plate is rotatably connected to the pressure base, and the other end of the second connecting plate is rotatably connected to the pressure plates.

[0018] A third connecting plate is provided between the second connecting plate and the pressure block, with one end of the third connecting plate rotatably connected to the second connecting plate and the other end of the third connecting plate rotatably connected to the pressure block;

[0019] A fourth connecting plate is provided between the lower end of the pressure relief base and the pressure dividing plate. One end of the fourth connecting plate is rotatably connected to the pressure relief base, and the other end of the fourth connecting plate is rotatably connected to the pressure dividing plate.

[0020] Furthermore, as a preferred embodiment, a support column is provided at the center of the secondary sleeve, and each of the elastic pressure relief devices is slidably sleeved on the support column through the pressure relief base; the upper end of the support column is connected to the column cap, and the lower end of the support column is connected to the hydraulic column.

[0021] Furthermore, as a preferred embodiment, the inner wall of the secondary sleeve is provided with three vertical rectangular grooves evenly distributed along the circumferential direction, and each pressure plate corresponds to each rectangular groove. The pressure plate moves horizontally along the radial direction of the secondary sleeve.

[0022] A method for using adaptive constant resistance roof support in coal mine pillarless mining includes the following steps:

[0023] S1. Under normal load: The hydraulic column and the elastic pressure relief device provide huge static friction force to the supporting roof, which is sufficient to support the pressure of the roadway roof. At this time, the multi-stage sleeve-type pressure relief column exhibits rigid support.

[0024] S2. When the roof pressure increases / sinks: When the mechanical pressure indicator detects that the roadway roof pressure exceeds the preset "constant resistance threshold", it transmits an electrical signal to the hydraulic column, controlling the hydraulic column pressure relief valve to open, so that the hydraulic column enters a follow-up extension and retraction state; under the action of the roadway roof pressure, the supporting roof applies downward pressure to the column cap, causing the column cap to drive the elastic pressure relief device and the secondary sleeve to slide downward; the secondary sleeve applies downward pressure to the worktable, and the worktable moves downward after being subjected to force, thereby transferring the load to the buffer spring and the support rod;

[0025] S3. Reset function: When the pressure on the roadway roof decreases, the hydraulic column, the elastic pressure relief device, and the spring buffer base push the secondary sleeve back to its original position, enabling cyclic use.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention employs a multi-stage sleeve-type pressure-relief column and an elastic pressure-relief device. Under pressure, the load borne by the pressure-bearing block is effectively distributed to the pressure-relief base and the pressure-distributing plate. The pressure-relief base slides downwards after being stressed to absorb some energy; simultaneously, the pressure-distributing plate moves radially along the rectangular groove during its downward sliding process, gradually bringing its outer edge into close contact with the inner wall of the secondary sleeve, thereby evenly distributing the remaining pressure to the sleeve wall surface. This design not only achieves multi-path pressure relief but also enhances the overall stability and load-bearing capacity of the support system through the adaptive contact of the pressure-distributing plate.

[0028] This invention employs a spring-loaded buffer base. The secondary sleeve applies downward pressure to the worktable, causing it to move downwards and transfer the load to the buffer spring and support rod. Through this process, the pressure on the secondary sleeve is effectively distributed to the buffer spring and support rod. The buffer spring, through compression deformation, relieves pressure, providing a constant and stable support resistance to the secondary sleeve, thereby achieving adaptive buffering and stable support against the pressure on the roof. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the support frame in this invention;

[0031] Figure 3 This is a schematic diagram of the multi-stage sleeve-type pressure-relief column in this invention;

[0032] Figure 4 This is a schematic diagram of the structure of the spring buffer base in this invention;

[0033] Figure 5 This is a schematic diagram of the elastic pressure relief device in this invention;

[0034] In the diagram: 1. Support frame; 11. Support base plate; 12. Support top plate; 13. Support side plate; 2. Multi-stage sleeve-type pressure relief column; 21. First-stage sleeve; 22. Second-stage sleeve; 23. Liquid inlet pipe; 24. Sealing buffer ring; 3. Spherical hinge base; 4. Column cap; 5. Hydraulic column; 6. Spring buffer base; 61. Workbench; 62. Support rod; 63. Base; 64. Buffer spring; 65. First connecting plate; 7. Elastic pressure relief device; 71. Pressure relief base; 72. Pressure bearing block; 73. High-elasticity spring sheet; 74. Pressure dividing plate; 75. Second connecting plate; 76. Third connecting plate; 77. Fourth connecting plate. Detailed Implementation

[0035] Please see Figures 1-5 In this embodiment of the invention, a coal mine pillarless development using roof adaptive constant resistance support equipment includes a support frame 1, which is composed of a support bottom plate 11, a support top plate 12 and a support side plate 13. The two ends of the support side plate 13 are rotatably connected to the support bottom plate 11 and the support top plate 12 respectively.

[0036] Four multi-stage sleeve-type pressure relief columns 2 are provided between the supporting base plate 11 and the supporting top plate 12. The four multi-stage sleeve-type pressure relief columns 2 are respectively connected to the four corners of the supporting base plate 11 and the supporting top plate 12.

[0037] In this embodiment, the top of the supporting top plate 12 is in contact with the top plate of the roadway, and the bottom of the supporting bottom plate 11 is in contact with the bottom plate of the roadway. The supporting top plate 12 is used to bear the pressure of the roadway top plate in the corresponding area and transmit the pressure to the multi-stage sleeve-type pressure relief column 2. The supporting bottom plate 11 is anchored on the roadway bottom plate to provide stable support for the multi-stage sleeve-type pressure relief column 2.

[0038] The tops of the four multi-stage sleeve-type pressure relief columns 2 are rotatably connected to the bottom of the supporting top plate 12; the bottoms of the four multi-stage sleeve-type pressure relief columns 2 are all provided with spherical hinge bases 3, and the bottoms of the spherical hinge bases 3 are hinged to the top of the supporting bottom plate 11; the spherical hinge bases 3 allow the multi-stage sleeve-type pressure relief columns 2 to adaptively adjust their posture when the roadway floor is uneven.

[0039] As a preferred embodiment, the multi-stage sleeve-type pressure relief column 2 includes a primary sleeve 21 fixed above the spherical hinge base 3, a secondary sleeve 22 coaxially embedded and slidably disposed inside the primary sleeve 21, and a sealing buffer ring 24 disposed between the upper end of the primary sleeve 21 and the secondary sleeve 22.

[0040] A hydraulic column 5 is coaxially arranged inside the primary sleeve 21, and the bottom of the hydraulic column 5 is fixed to the upper end face of the spherical hinge base 3; an inlet pipe 23 connected to the hydraulic column 5 is vertically arranged on the outside of the primary sleeve 21; a spring buffer base 6 is coaxially arranged inside the primary sleeve 21, and one end of the hydraulic column 5 is slidably connected to the spring buffer base 6; the upper end of the spring buffer base 6 is fixed to the lower end face of the secondary sleeve 22; the hydraulic column 5 provides the main supporting force for supporting the top plate 12.

[0041] Several elastic pressure relief devices 7 are coaxially arranged inside the secondary casing 22. The uppermost elastic pressure relief device 7 is equipped with a cap 4 that is slidably connected to the secondary casing 22. A mechanical pressure indicator (not shown in the figure) is installed inside the cap 4 to monitor the pressure changes of the roadway roof in real time.

[0042] In this embodiment, the spring buffer base 6 includes a worktable 61 sleeved on the outside of the hydraulic column 5. The upper part of the worktable 61 is fixed to the lower end face of the secondary sleeve 22. Three evenly distributed support rods 62 are vertically arranged along the circumferential direction below the worktable 61, and the upper end of each support rod 62 is rotatably connected to the bottom of the worktable 61.

[0043] A base 63 is coaxially arranged below the workbench 61 and sleeved on the outside of the hydraulic column 5. A buffer spring 64 is arranged between the base 63 and the workbench 61 and sleeved on the outside of the hydraulic column 5. A first connecting plate 65 is arranged between the base 63 and each support rod 62. One end of the first connecting plate 65 is rotatably connected to the base 63 and the other end of the first connecting plate 65 is rotatably connected to the support rod 62.

[0044] When the roof pressure increases / sinks: the secondary sleeve 22 moves downwards and applies downward pressure to the worktable 61; the worktable 61 moves downwards under the force, thereby transferring the load to the buffer spring 64 and the support rod 62. Through this process, the pressure on the secondary sleeve 22 is effectively distributed to the buffer spring 64 and the support rod 62; the buffer spring 64 relieves pressure through compression deformation, providing constant and stable support resistance for the secondary sleeve 22, thereby achieving adaptive buffering and stable support against the roof pressure.

[0045] In this embodiment, three vertical wedge-shaped grooves (not shown in the figure) are uniformly opened along the circumferential direction on the inner wall of the primary sleeve 21. The depth of the wedge-shaped grooves increases from top to bottom. The wedge-shaped grooves are located at the upper end of the primary sleeve, and the length of the wedge-shaped grooves is half of the primary sleeve. Each support rod 62 corresponds to each wedge-shaped groove, and the spring buffer base 6 moves up and down along the vertical direction of the wedge-shaped grooves.

[0046] When the top plate presses down / sinks: the secondary sleeve 22 drives the spring buffer base 6 to slide downward. During this process, the support rod 62 moves synchronously along the wedge-shaped groove. When the support rod 62 slides to the bottom of the wedge-shaped groove, the spring buffer base 6 is locked and the positioning is completed.

[0047] In this embodiment, the elastic pressure relief device 7 includes a pressure relief base 71, which has a hollow structure inside; a pressure-bearing block 72 is slidably disposed above the pressure relief base 71; and a plurality of highly elastic spring sheets 73 are sleeved at the connection between the pressure-bearing block 72 and the pressure relief base 71.

[0048] The lower end of the pressure relief base 71 is connected to the pressure-bearing block 72 in the adjacent lower elastic pressure relief device 7;

[0049] Three evenly distributed pressure plates 74 are vertically arranged on the outside of the pressure base 71 along the circumferential direction. A second connecting plate 75 is provided between the upper end of the pressure base 71 and the pressure plates 74. One end of the second connecting plate 75 is rotatably connected to the pressure base 71, and the other end of the second connecting plate 75 is rotatably connected to the pressure plates 74.

[0050] A third connecting plate 76 is provided between the second connecting plate 75 and the pressure block 72. One end of the third connecting plate 76 is rotatably connected to the second connecting plate 75, and the other end of the third connecting plate 76 is rotatably connected to the pressure block 72.

[0051] A fourth connecting plate 77 is provided between the lower end of the pressure base 71 and the pressure dividing plate 74. One end of the fourth connecting plate 77 is rotatably connected to the pressure base 71, and the other end of the fourth connecting plate 77 is rotatably connected to the pressure dividing plate 74.

[0052] When the top plate presses down / sinks: Under the pressure of the top plate, the supporting top plate 12 applies downward pressure to the column cap 4, causing the column cap 4 to slide downward along the secondary sleeve 22. During the downward movement, the column cap 4 applies a load to the bearing block 72, which then transmits the pressure to the high-elasticity spring sheet 73 and the third connecting plate 76. Specifically, the high-elasticity spring sheet 73 transmits the load to the pressure relief base 71, and the third connecting plate 76 transmits the load to the pressure distribution plate 74 through the second connecting plate 75. Through these two paths, the pressure on the bearing block 72 is effectively distributed to the pressure relief base 71 and the pressure distribution plate 74. During this process, the high-elasticity spring sheet 73 achieves pressure relief through compression deformation, continuously providing constant and stable support resistance to the column cap 4, thereby achieving adaptive buffering and stable support against the pressure of the top plate.

[0053] In a preferred embodiment, a support column (not shown in the figure) is provided in the center of the secondary sleeve 22, and each elastic pressure relief device 7 is slidably sleeved on the outside of the support column through the pressure relief base 71; the upper end of the support column is connected to the column cap 4, and the lower end of the support column is connected to the hydraulic column 5.

[0054] In this embodiment, three vertical rectangular grooves (not shown in the figure) are evenly opened on the inner wall of the secondary sleeve 22 along the circumferential direction. Each pressure plate 74 corresponds to each rectangular groove, and the pressure plate 74 moves horizontally along the radial direction of the secondary sleeve 22.

[0055] When the top plate presses down / sinks: Under pressure, the load borne by the bearing block 72 is effectively distributed to the pressure relief base 71 and the pressure distribution plate 74. The pressure relief base 71 slides downwards after being subjected to force to absorb some energy; simultaneously, the pressure distribution plate 74 moves radially along the rectangular groove during its downward sliding process, gradually bringing its outer edge into close contact with the inner wall of the secondary casing 22, thereby evenly distributing the remaining pressure to the casing wall surface. This design not only achieves multi-path pressure relief but also enhances the overall stability and load-bearing capacity of the support system through the adaptive contact of the pressure distribution plate 74.

[0056] A method for using adaptive constant resistance roof support in coal mine pillarless mining includes the following steps:

[0057] S1. Under normal load: The hydraulic column 5 and the elastic pressure relief device 7 provide huge static friction force to support the roof 12, which is sufficient to support the pressure of the roadway roof. At this time, the multi-stage sleeve pressure relief column 2 exhibits rigid support.

[0058] S2. When the roof pressure increases / sinks: When the mechanical pressure indicator detects that the roadway roof pressure exceeds the preset "constant resistance threshold", it transmits an electrical signal to the hydraulic column 5, controlling the hydraulic column 5 to open the pressure relief valve, causing the hydraulic column 5 to enter a follow-up extension and retraction state; under the action of the roadway roof pressure, the supporting roof 12 applies downward pressure to the column cap 4, causing the column cap 4 to drive the elastic pressure relief device 7 and the secondary sleeve 22 to slide downward. During the downward movement, the column cap 4 applies a load to the pressure-bearing block 72, and the pressure-bearing block 72 then transmits the pressure it receives to the high-elasticity spring plate 73 and the third connecting plate 76 respectively.

[0059] Specifically, the high-elasticity spring sheet 73 transfers the load to the pressure-relief base 71, and the third connecting plate 76 transfers the load to the pressure-distributing plate 74 through the second connecting plate 75. Through these two paths, the pressure on the bearing block 72 is effectively distributed to the pressure-relief base 71 and the pressure-distributing plate 74. In this process, the high-elasticity spring sheet 73 achieves pressure relief through compression deformation, continuously providing a constant and stable support resistance to the column cap 4, thereby achieving adaptive buffering and stable support against the pressure on the top plate.

[0060] The pressure base 71 slides downwards under pressure to absorb some of the energy. Simultaneously, the pressure-distributing plate 74 moves radially along the rectangular groove as it slides downwards, gradually bringing its outer edge into close contact with the inner wall of the secondary casing 22, thus evenly distributing the remaining pressure to the casing wall. This design not only achieves multi-path pressure relief but also enhances the overall stability and load-bearing capacity of the support system through the adaptive contact of the pressure-distributing plate 74.

[0061] The secondary sleeve 22 applies downward pressure to the worktable 61. Under this pressure, the worktable 61 moves downward, transferring the load to the buffer spring 64 and the support rod 62. Through this process, the pressure on the secondary sleeve 22 is effectively distributed to the buffer spring 64 and the support rod 62. The buffer spring 64, through compression deformation, relieves pressure, providing a constant and stable support resistance to the secondary sleeve 22, thereby achieving adaptive buffering and stable support against the pressure on the roof.

[0062] S3. Reset Function: When the pressure on the tunnel roof decreases, the hydraulic column 5 pressurizes, driving the column cap 4 upward through the support column; as the column cap 4 moves upward, the high-elasticity spring plate 73 releases pressure, causing the elastic pressure relief device 7 to reset. After the column cap 4 moves to a certain height, it is limited and drives the secondary sleeve 22 to move upward synchronously; at the same time, the buffer spring 64 releases pressure, and the secondary sleeve 22 drives the spring buffer base 6 to move upward; the entire device returns to the normal load-bearing state.

[0063] When the pressure on the tunnel roof exceeds the preset "constant resistance threshold," it adapts to the movement of the surrounding rock through the elastic pressure relief device 7 and the spring buffer base 6. During this process, the multi-stage sleeve-type pressure relief column 2 continuously provides a basically constant supporting force to the surrounding rock, thereby avoiding damage due to excessive force. It works in synergy with the surrounding rock in a "rigid-flexible" manner, maintaining stable support while allowing moderate deformation of the surrounding rock, ultimately achieving the joint bearing capacity of the support structure and the surrounding rock.

[0064] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A coal mine pillarless excavation equipment with adaptive constant resistance roof support, characterized in that: It includes a support frame (1), which is composed of a support base plate (11), a support top plate (12) and a support side plate (13). The two ends of the support side plate (13) are rotatably connected to the support base plate (11) and the support top plate (12) respectively. Four multi-stage sleeve-type pressure relief columns (2) are provided between the supporting base plate (11) and the supporting top plate (12). The four multi-stage sleeve-type pressure relief columns (2) are respectively connected to the four corners of the supporting base plate (11) and the supporting top plate (12).

2. The coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 1, characterized in that: The top of the supporting top plate (12) is in contact with the top of the roadway, and the bottom of the supporting bottom plate (11) is in contact with the bottom of the roadway. The tops of the four multi-stage sleeve-type pressure relief columns (2) are rotatably connected to the bottom of the supporting top plate (12); the bottoms of the four multi-stage sleeve-type pressure relief columns (2) are all provided with spherical hinge bases (3), and the bottoms of the spherical hinge bases (3) are hinged to the top of the supporting bottom plate (11).

3. The coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 2, characterized in that: The multi-stage sleeve-type pressure relief column (2) includes a first-stage sleeve (21) fixed above the spherical hinge base (3), and a second-stage sleeve (22) is coaxially embedded and slidably arranged inside the first-stage sleeve (21). A sealing buffer ring (24) is provided between the upper end of the first-stage sleeve (21) and the second-stage sleeve (22). A hydraulic column (5) is coaxially arranged inside the first-stage sleeve (21), and the bottom of the hydraulic column (5) is fixed to the upper end face of the spherical hinge base (3); an inlet pipe (23) connected to the hydraulic column (5) is vertically arranged on the outside of the first-stage sleeve (21); a spring buffer base (6) is coaxially arranged inside the first-stage sleeve (21), and one end of the hydraulic column (5) is slidably connected to the spring buffer base (6); the upper end of the spring buffer base (6) is fixed to the lower end face of the second-stage sleeve (22); The secondary sleeve (22) is coaxially provided with several elastic pressure relief devices (7), and the uppermost elastic pressure relief device (7) is provided with a column cap (4) that is slidably connected to the secondary sleeve (22); a mechanical pressure indicator is installed inside the column cap (4).

4. A coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 3, characterized in that: The spring buffer base (6) includes a worktable (61) sleeved on the outside of the hydraulic column (5), the upper part of the worktable (61) is fixed to the lower end face of the secondary sleeve (22); three evenly distributed support rods (62) are vertically arranged along the circumferential direction below the worktable (61), and the upper end of each support rod (62) is rotatably connected to the bottom of the worktable (61). A base (63) is coaxially arranged below the workbench (61) and sleeved on the outside of the hydraulic column (5). A buffer spring (64) is arranged between the base (63) and the workbench (61). The buffer spring (64) is sleeved on the outside of the hydraulic column (5). A first connecting plate (65) is arranged between the base (63) and each of the support rods (62). One end of the first connecting plate (65) is rotatably connected to the base (63), and the other end of the first connecting plate (65) is rotatably connected to the support rod (62).

5. A coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 4, characterized in that: The inner wall of the primary sleeve (21) is uniformly provided with three vertical wedge-shaped grooves along the circumferential direction, and the depth of the wedge-shaped grooves increases from top to bottom; the wedge-shaped grooves are located at the upper end of the primary sleeve (21), and the length of the wedge-shaped grooves is half the length of the primary sleeve (21); each of the support rods (62) corresponds to each of the wedge-shaped grooves, and the spring buffer base (6) moves up and down along the vertical direction of the wedge-shaped grooves.

6. A coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 3, characterized in that: The elastic pressure relief device (7) includes a pressure relief base (71), which has a hollow structure inside; a pressure-bearing block (72) is slidably arranged above the pressure relief base (71); and a plurality of highly elastic spring sheets (73) are sleeved at the connection between the pressure-bearing block (72) and the pressure relief base (71). The lower end of the pressure relief base (71) is connected to the pressure-bearing block (72) in the adjacent lower elastic pressure relief device (7); The pressure relief base (71) has three evenly distributed pressure plates (74) vertically arranged along the circumferential direction on its outside. A second connecting plate (75) is provided between the upper end of the pressure relief base (71) and the pressure plates (74). One end of the second connecting plate (75) is rotatably connected to the pressure relief base (71), and the other end of the second connecting plate (75) is rotatably connected to the pressure plates (74). A third connecting plate (76) is provided between the second connecting plate (75) and the pressure block (72). One end of the third connecting plate (76) is rotatably connected to the second connecting plate (75), and the other end of the third connecting plate (76) is rotatably connected to the pressure block (72). A fourth connecting plate (77) is provided between the lower end of the pressure relief base (71) and the pressure dividing plate (74). One end of the fourth connecting plate (77) is rotatably connected to the pressure relief base (71), and the other end of the fourth connecting plate (77) is rotatably connected to the pressure dividing plate (74).

7. A coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 6, characterized in that: The secondary sleeve (22) has a support column in the center, and each elastic pressure relief device (7) is slidably sleeved on the support column through the pressure relief base (71); the upper end of the support column is connected to the column cap (4), and the lower end of the support column is connected to the hydraulic column (5).

8. A coal mine pillarless excavation equipment with adaptive constant resistance roof support according to claim 7, characterized in that: The inner wall of the secondary sleeve (22) is uniformly provided with three vertical rectangular grooves along the circumferential direction. Each pressure plate (74) corresponds to each rectangular groove. The pressure plate (74) moves horizontally along the radial direction of the secondary sleeve (22).

9. A method for using adaptive constant resistance roof support in pillarless coal mine development, comprising using a pillarless coal mine development equipment as described in any one of claims 1-8, characterized in that, It includes the following steps: S1. Under normal load: The hydraulic column (5) and the elastic pressure relief device (7) provide huge static friction force to the supporting roof plate (12), which is sufficient to support the pressure of the roadway roof plate. At this time, the multi-stage sleeve pressure relief column (2) exhibits rigid support. S2. When the roof pressure increases / sinks: When the mechanical pressure indicator detects that the roadway roof pressure exceeds the preset "constant resistance threshold", it transmits an electrical signal to the hydraulic column (5) to control the hydraulic column (5) pressure relief valve to open, so that the hydraulic column (5) enters the follow-up extension and retraction state; under the action of the roadway roof pressure, the supporting roof (12) applies downward pressure to the column cap (4), causing the column cap (4) to drive the elastic pressure relief device (7) and the secondary sleeve (22) to slide downward; the secondary sleeve (22) applies downward pressure to the worktable (61), and the worktable (61) moves downward after being subjected to force, thereby transferring the load to the buffer spring (64) and the support rod (62). S3. Reset function: When the pressure on the roof of the roadway decreases, the hydraulic column (5), the elastic pressure relief device (7) and the spring buffer base (6) push the secondary sleeve (22) back to its original position to achieve cyclic use.

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