Three-way coal stress monitoring device

Abstract

A mining three-way coal stress monitoring device comprises an axial stress applying head, a three-way stress integration device and an outer supporting assembly, the axial stress applying head is connected with one end of the three-way stress integration device, the other end of the three-way stress integration device is connected with the outer supporting assembly, and the axial stress applying head, the three-way stress integration device and the outer supporting assembly are located on the same axis. The axial stress applying head, the three-way stress integration device and the outer supporting assembly are wrapped into a whole through a hard plastic wrapping body; the stress in the axial direction, the horizontal direction and the vertical direction of a drill hole is monitored in the mode that the axial stress applying head actively applies pressure to the three-direction stress integration device, strain gauges are installed in the horizontal direction and the vertical direction of the three-direction stress integration device for passive pressure bearing, and the outer supporting assembly externally supports the wall of the drill hole for pressure maintaining, operation is easy, the stress in the three directions of a coal body is monitored, and the coal body stress monitoring accuracy is improved. The problems that an existing stress monitoring device is tedious in installation process and cannot identify the stress direction are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal body stress monitoring equipment and relates to a three-way coal body stress monitoring device. Background Art

[0002] The surrounding rock stress of the working face is the basic data support for studying the fracture and deformation laws of the surrounding rock and the risk and hidden danger investigation of the mining area. With the gradual increase in the depth of coal resource mining, the impact of rock pressure and other mine pressure problems are becoming more and more serious. Coal body stress monitoring equipment has become an essential means of mine monitoring and research.

[0003] The current coal body stress monitoring devices mainly include unidirectional stress monitoring equipment and oil pressure pillow type stress monitoring equipment. The unidirectional stress monitoring equipment requires the strain gauge to remain horizontal during installation, and can only measure stress in the vertical direction, and the measurement result is single. The oil pressure pillow type stress monitoring equipment needs to inject oil into the oil pressure pillow to apply pressure and fix it in the borehole. The stress is monitored by squeezing the oil pressure pillow through the deformation of the surrounding rock. The installation process is cumbersome and can only monitor the magnitude of stress, but cannot identify the direction of stress. In addition, the oil pipe is prone to bending in the borehole and does not maintain pressure, which will affect the measurement results. It can be seen that the existing stress monitoring equipment has a cumbersome installation process and cannot identify the stress direction. The measurement results are single and can no longer meet the actual work needs. It is urgent to design a stress monitoring equipment with a simple installation process and the ability to identify the stress direction. Summary of the invention

[0004] The purpose of the present invention is to provide a three-way coal body stress monitoring device, which solves the problem that the existing stress monitoring device in the prior art has a complicated installation process and cannot identify the stress direction.

[0005] The technical solution adopted by the present invention is a three-dimensional coal body stress monitoring device for mining, comprising an axial stress applying head, a three-dimensional stress integration device, and an external support assembly. The axial stress applying head is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress applying head, the three-dimensional stress integration device, and the external support assembly are located on the same axis, and the axial stress applying head, the three-dimensional stress integration device, and the external support assembly are wrapped as a whole by a hard plastic package. The present invention is also characterized in that: The material of the hard plastic package body is any one of PVC material and rubber material.

[0006] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head is a rectangular parallelepiped, and the bottom of the axial stress applying head is coaxially connected to the three-axis stress integration device.

[0007] The three-axis stress integration device includes a strain box, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head. Strain gauges are installed on the six surfaces of the strain box, and stress gaskets are installed on the outer sides of the four strain gauges located on the vertical and horizontal surfaces of the strain box. The outer surfaces of the stress gaskets are in contact with the inner wall of the hard plastic package; one end of the four stress gaskets extends toward the direction of the axial stress pressure head and forms a pressure head cavity. The bottom of the axial stress pressure head slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets are fixed to the outer support assembly; A gasket gap is provided between the four stress gaskets and the side wall of the axial stress applying head, a strain gap is provided between the strain gauge located on the axial surface of the strain box and the bottom surface of the axial stress applying head, and the distance of the gasket gap is greater than the distance of the strain gap.

[0008] A plurality of round beads are matched and arranged in the gasket gaps between the four stress gaskets and the side walls of the axial stress applying head.

[0009] The external support assembly comprises an external support cylinder body, one end of the external support cylinder body is a disc, the other end of the external support cylinder body is a cylinder, the diameter of the disc is larger than the diameter of the cylinder, and the end surface of the disc is fixedly connected to four stress washers; A circular through hole is opened inside the cylindrical end of the external support cylinder body along the axial direction, and an external support rod is coaxially sleeved in the circular through hole. A sliding gap is provided between the external support rod and the disc end of the external support cylinder body. A plurality of groups of reserved holes are arranged at intervals along the length direction on the side wall of the cylindrical end of the external support cylinder body, and the opening direction of the reserved holes is perpendicular to the axis of the cylindrical end of the external support cylinder body. A plurality of groups of external support bones are arranged at intervals along the length direction on the side wall of the external support rod, and one end of the external support bone is hinged to the side wall of the external support rod, and the other end of the external support bone passes through the reserved hole and is hinged to the external support gasket.

[0010] The number of external support bones corresponds to the number of reserved holes.

[0011] The beneficial effects of the present invention are: The mining three-dimensional coal body stress monitoring device of the present invention actively applies pressure to the three-dimensional stress integration device through an axial stress pressure head, passively bears pressure by strain gauges installed in the three-dimensional stress integration device in the horizontal and vertical directions, and monitors the three-directional stress of the borehole in the axial, horizontal and vertical directions by an external support component to maintain pressure. The device is simple to operate and realizes three-directional stress monitoring of the coal body, thus solving the problems of complicated installation process and inability to identify stress direction of existing stress monitoring devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a three-dimensional coal body stress monitoring device for mining according to the present invention; Figure 2 It is a structural schematic diagram of a three-dimensional stress integration device in a three-dimensional coal body stress monitoring device for mining of the present invention; Figure 3 It is a structural schematic diagram of the external support assembly in the three-way coal body stress monitoring device for mining of the present invention.

[0013] In the figure, 1. drill hole, 2. hard plastic package, 3. axial stress pressure head, 4. strain box, 5. strain gauge, 6. stress gasket, 7. ball, 8. external support cylinder, 9. external support rod, 10. reserved hole, 11. external support bone, 12. external support gasket. DETAILED DESCRIPTION

[0014] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] The three-dimensional coal body stress monitoring device for mining of the present invention is as follows: Figure 1 As shown, it includes an axial stress pressing head 3, a three-dimensional stress integration device, and an external support component. The axial stress pressing head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support component. The axial stress pressing head 3, the three-dimensional stress integration device, and the external support component are located on the same axis. The axial stress pressing head 3, the three-dimensional stress integration device, and the external support component are wrapped as a whole by a hard plastic package 2. The axial stress pressing head 3 can apply pressure to the three-dimensional stress integration device, and the three-dimensional stress integration device can monitor stress in three directions. The external support component can fix the three-dimensional stress integration device on the inner wall of the borehole 1.

[0016] Among them, the three-directional stress integration device is actively pressurized by the axial stress pressure head 3, the three-directional stress integration device is passively pressurized in the horizontal and vertical directions, and the external support component externally supports the wall of the borehole 1 to maintain pressure, so as to monitor the three-directional stress of the borehole 1 in the axial, horizontal and vertical directions. The operation is simple, and the three-directional stress monitoring of the coal body is realized, which solves the problem that the existing stress monitoring device has a cumbersome installation process and cannot identify the stress direction.

[0017] The material of the hard plastic package 2 is any one of polyvinyl chloride (PVC) material and rubber material. Both PVC material and rubber material have certain plasticity and can be elastically deformed when squeezed by external force. The top outer surface of the stress pressure head is a smooth curved surface structure, which is convenient for fitting with the inner wall of the hard plastic package 2. The bottom of the axial stress pressure head 3 is in a rectangular parallelepiped shape, and the bottom of the axial stress pressure head 3 is coaxially connected to the three-axis stress integration device.

[0018] Three-dimensional stress integration device, such as Figure 2As shown, the three-axis stress integration device includes a strain box 4, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box 4 are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head 3, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head 3. Strain gauges 5 are correspondingly installed on the six surfaces of the strain box 4. The strain gauges 5 can monitor the stresses in the directions corresponding to the two vertical surfaces, two axial surfaces, and two horizontal surfaces of the strain box 4. The strain gauges 5 are located on the vertical surfaces of the strain box 4. Stress washers 6 are installed correspondingly on the outer sides of the four strain gauges 5 on the horizontal plane, and the outer surfaces of the stress washers 6 are in contact with the inner walls of the hard plastic package 2; the stress washers 6 protect the strain gauges 5, and one end of the four stress washers 6 extends toward the direction of the axial stress applying head 3 to form a pressure head cavity, and the bottom of the axial stress applying head 3 slides inside the pressure head cavity along the axial direction, and the axial stress applying head 3 applies pressure to the strain box 4 by sliding inside the pressure head cavity, thereby squeezing the strain gauges 5 on the vertical plane, and the other ends of the four stress washers 6 are fixedly connected to the external support assembly.

[0019] The axial stress pressure head 3 actively applies pressure to the strain gauge 5 on the axial surface of the strain box 4, and the strain gauges 5 on the horizontal and vertical surfaces of the strain box 4 are passively subjected to pressure, so as to monitor the stress in three directions of the axial, horizontal and vertical directions of the borehole 1, thereby realizing the three-directional stress monitoring of the coal body.

[0020] A gasket gap is provided between the four stress gaskets 6 and the side wall of the axial stress applying head 3, a strain gap is provided between the strain gauge 5 located on the axial surface of the strain box 4 and the bottom surface of the axial stress applying head 3, and the distance of the gasket gap is greater than the distance of the strain gap.

[0021] A plurality of round balls 7 are matched and arranged in the gasket gap between the stress gasket 6 and the side wall of the axial stress applying head 3 , and the stress gasket 6 and the side wall of the axial stress applying head 3 can be slidably connected through the round balls 7 .

[0022] External support components, such as Figure 3 As shown, the external support assembly includes an external support cylinder body 8, one end of the external support cylinder body 8 is a disc, and the other end of the external support cylinder body 8 is a cylinder. The diameter of the disc is larger than the diameter of the cylinder, and the end surface of the disc is fixedly connected to four stress washers 6; A circular through hole is provided inside the cylindrical end of the external support cylinder 8 along the axial direction, and an external support rod 9 is coaxially sleeved in the circular through hole of the external support cylinder 8, and a sliding gap is provided between the external support rod 9 and the disc end of the external support cylinder 8, and a plurality of groups of reserved holes 10 are distributed at intervals along the length direction on the side wall of the cylindrical end of the external support cylinder 8, and the opening direction of the reserved holes 10 is perpendicular to the axis of the cylindrical end of the external support cylinder 8, and a plurality of groups of external support bones 11 are distributed at intervals along the length direction on the side wall of the external support rod 9, and one end of the external support bone 11 is hinged to the side wall of the external support rod 9, and the other end of the external support bone 11 passes through the reserved hole 10 and is hinged to the external support gasket 12. The number of the external support bones 11 corresponds to the number of the reserved holes 10.

[0023] By pushing the external support rod 9 axially forward in the cavity of the external support cylinder 8, the external support bone 11 is driven to open the external support gasket 12 so that the external support gasket 12 is closely attached to the inner wall of the borehole 1, so as to fix the entire device at the bottom of the borehole 1 to prevent it from slipping. The method of maintaining the pressure of the borehole 1 wall by the external support assembly ensures that the three-dimensional stress integration device monitors the three-dimensional stress of the borehole 1 in the axial, horizontal and vertical directions, and the whole process is simple to operate.

[0024] The working principle of the three-dimensional coal body stress monitoring device for mining of the present invention is as follows: During operation, first determine the vertical and horizontal directions of the borehole 1 according to the monitoring requirements, then keep the vertical and horizontal planes of the strain box 4 consistent with the vertical and horizontal directions of the borehole 1, and slowly push the three-dimensional coal body stress monitoring device to the bottom of the borehole 1 so that the bottom of the borehole 1 bears against the axial stress pressure head 3. Continue to push the three-dimensional coal body stress monitoring device so that the axial stress pressure head 3 squeezes the strain gauge 5 on the axial surface of the strain box 4 until the pressure reaches the set pressure; finally, push the external support rod 9 to open the external support gasket 12 so that the external support gasket 12 is tightly attached to the inner wall of the borehole 1, thereby preventing the three-dimensional coal body stress monitoring device from slipping.

[0025] When the surrounding rock is deformed, the strain gauge 5 on the strain box 4 will be squeezed, and the stress change of the coal rock mass is monitored through the resistance strain effect of the strain gauge 5, thereby realizing the monitoring of the stress conditions in the axial direction, vertical direction and horizontal direction in the coal rock borehole 1.

[0026] The three-dimensional coal body stress monitoring device for mining of the present invention has the following specific embodiments: Example 1 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0027] Example 2 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0028] The material of the hard plastic package 2 is any one of PVC material and rubber material.

[0029] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head 3 is a rectangular parallelepiped, and the bottom of the axial stress applying head 3 is coaxially connected to the three-axis stress integration device.

[0030] Example 3 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0031] The material of the hard plastic package 2 is any one of PVC material and rubber material.

[0032] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head 3 is a rectangular parallelepiped, and the bottom of the axial stress applying head 3 is coaxially connected to the three-axis stress integration device.

[0033] The three-axis stress integration device includes a strain box 4, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box 4 are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head 3, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head 3. Strain gauges 5 are correspondingly installed on the six surfaces of the strain box 4, and stress gaskets 6 are correspondingly installed on the outer sides of the four strain gauges 5 located on the vertical surface and the horizontal surface of the strain box 4. The outer surface of the stress gasket 6 is in contact with the inner wall of the hard plastic package 2; one end of the four stress gaskets 6 extends toward the direction of the axial stress pressure head 3 and forms a pressure head cavity, the bottom of the axial stress pressure head 3 slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets 6 are fixed to the outer support assembly; Example 4 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0034] The material of the hard plastic package 2 is any one of PVC material and rubber material.

[0035] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head 3 is a rectangular parallelepiped, and the bottom of the axial stress applying head 3 is coaxially connected to the three-axis stress integration device.

[0036] The three-axis stress integration device includes a strain box 4, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box 4 are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head 3, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head 3. Strain gauges 5 are correspondingly installed on the six surfaces of the strain box 4, and stress gaskets 6 are correspondingly installed on the outer sides of the four strain gauges 5 located on the vertical surface and the horizontal surface of the strain box 4. The outer surface of the stress gasket 6 is in contact with the inner wall of the hard plastic package 2; one end of the four stress gaskets 6 extends toward the direction of the axial stress pressure head 3 and forms a pressure head cavity, the bottom of the axial stress pressure head 3 slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets 6 are fixed to the outer support assembly; A gasket gap is provided between the four stress gaskets 6 and the side wall of the axial stress applying head 3, a strain gap is provided between the strain gauge 5 located on the axial surface of the strain box 4 and the bottom surface of the axial stress applying head 3, and the distance of the gasket gap is greater than the distance of the strain gap.

[0037] A plurality of round balls 7 are matched and arranged in the gasket gaps between the four stress gaskets 6 and the side walls of the axial stress applying head 3 .

[0038] Example 5 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0039] The material of the hard plastic package 2 is any one of PVC material and rubber material.

[0040] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head 3 is a rectangular parallelepiped, and the bottom of the axial stress applying head 3 is coaxially connected to the three-axis stress integration device.

[0041] The three-axis stress integration device includes a strain box 4, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box 4 are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head 3, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head 3. Strain gauges 5 are correspondingly installed on the six surfaces of the strain box 4, and stress gaskets 6 are correspondingly installed on the outer sides of the four strain gauges 5 located on the vertical surface and the horizontal surface of the strain box 4. The outer surface of the stress gasket 6 is in contact with the inner wall of the hard plastic package 2; one end of the four stress gaskets 6 extends toward the direction of the axial stress pressure head 3 and forms a pressure head cavity, the bottom of the axial stress pressure head 3 slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets 6 are fixed to the outer support assembly; A gasket gap is provided between the four stress gaskets 6 and the side wall of the axial stress applying head 3, a strain gap is provided between the strain gauge 5 located on the axial surface of the strain box 4 and the bottom surface of the axial stress applying head 3, and the distance of the gasket gap is greater than the distance of the strain gap.

[0042] A plurality of round balls 7 are matched and arranged in the gasket gaps between the four stress gaskets 6 and the side walls of the axial stress applying head 3 .

[0043] The external support assembly includes an external support cylinder 8, one end of the external support cylinder 8 is a disc, the other end of the external support cylinder 8 is a cylinder, the diameter of the disc is larger than the diameter of the cylinder, and the end surface of the disc is fixedly connected to four stress washers 6; A circular through hole is opened inside the cylindrical end of the external support cylinder body 8 along the axial direction, and an external support rod 9 is coaxially sleeved in the circular through hole. A sliding gap is provided between the external support rod 9 and the disc end of the external support cylinder body 8. A plurality of groups of reserved holes 10 are distributed at intervals along the length direction on the side wall of the cylindrical end of the external support cylinder body 8. The opening direction of the reserved holes 10 is perpendicular to the axis of the cylindrical end of the external support cylinder body 8. A plurality of groups of external support bones 11 are distributed at intervals along the length direction on the side wall of the external support rod 9. One end of the external support bone 11 is hinged to the side wall of the external support rod 9, and the other end of the external support bone 11 passes through the reserved hole 10 and is hinged to the external support gasket 12.

[0044] Example 6 The three-dimensional coal body stress monitoring device for mining comprises an axial stress pressure head 3, a three-dimensional stress integration device, and an external support assembly. The axial stress pressure head 3 is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support assembly. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are located on the same axis. The axial stress pressure head 3, the three-dimensional stress integration device, and the external support assembly are wrapped together by a hard plastic package 2.

[0045] The material of the hard plastic package 2 is any one of PVC material and rubber material.

[0046] The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head 3 is a rectangular parallelepiped, and the bottom of the axial stress applying head 3 is coaxially connected to the three-axis stress integration device.

[0047] The three-axis stress integration device includes a strain box 4, which is in the shape of a rectangular parallelepiped as a whole. The six surfaces of the strain box 4 are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces. The axial surface is perpendicular to the axis of the axial stress pressure head 3, and the vertical surface and the horizontal surface are parallel to the axis of the axial stress pressure head 3. Strain gauges 5 are correspondingly installed on the six surfaces of the strain box 4, and stress gaskets 6 are correspondingly installed on the outer sides of the four strain gauges 5 located on the vertical surface and the horizontal surface of the strain box 4. The outer surface of the stress gasket 6 is in contact with the inner wall of the hard plastic package 2; one end of the four stress gaskets 6 extends toward the direction of the axial stress pressure head 3 and forms a pressure head cavity, the bottom of the axial stress pressure head 3 slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets 6 are fixed to the outer support assembly; A gasket gap is provided between the four stress gaskets 6 and the side wall of the axial stress applying head 3, a strain gap is provided between the strain gauge 5 located on the axial surface of the strain box 4 and the bottom surface of the axial stress applying head 3, and the distance of the gasket gap is greater than the distance of the strain gap.

[0048] A plurality of round balls 7 are matched and arranged in the gasket gaps between the four stress gaskets 6 and the side walls of the axial stress applying head 3 .

[0049] The external support assembly includes an external support cylinder 8, one end of the external support cylinder 8 is a disc, the other end of the external support cylinder 8 is a cylinder, the diameter of the disc is larger than the diameter of the cylinder, and the end surface of the disc is fixedly connected to four stress washers 6; A circular through hole is opened inside the cylindrical end of the external support cylinder body 8 along the axial direction, and an external support rod 9 is coaxially sleeved in the circular through hole. A sliding gap is provided between the external support rod 9 and the disc end of the external support cylinder body 8. A plurality of groups of reserved holes 10 are distributed at intervals along the length direction on the side wall of the cylindrical end of the external support cylinder body 8. The opening direction of the reserved holes 10 is perpendicular to the axis of the cylindrical end of the external support cylinder body 8. A plurality of groups of external support bones 11 are distributed at intervals along the length direction on the side wall of the external support rod 9. One end of the external support bone 11 is hinged to the side wall of the external support rod 9, and the other end of the external support bone 11 passes through the reserved hole 10 and is hinged to the external support gasket 12.

[0050] The number of the external support bones 11 corresponds to the number of the reserved holes 10 .

Claims

1. A three-dimensional coal body stress monitoring device for mining, characterized in that: The device comprises an axial stress pressure head (3), a three-dimensional stress integration device, and an external support component. The axial stress pressure head (3) is connected to one end of the three-dimensional stress integration device, and the other end of the three-dimensional stress integration device is connected to the external support component. The axial stress pressure head (3), the three-dimensional stress integration device, and the external support component are located on the same axis. The axial stress pressure head (3), the three-dimensional stress integration device, and the external support component are wrapped together by a hard plastic package (2).

2. The three-dimensional coal body stress monitoring device for mining according to claim 1 is characterized in that: The material of the hard plastic package (2) is any one of PVC material and rubber material.

3. The three-dimensional coal body stress monitoring device for mining according to claim 2 is characterized in that: The top outer surface of the stress applying head is a smooth curved structure, the bottom of the axial stress applying head (3) is in the shape of a rectangular parallelepiped, and the bottom of the axial stress applying head (3) is coaxially connected to the three-axis stress integration device.

4. The three-dimensional coal body stress monitoring device for mining according to claim 3 is characterized in that: The three-axis stress integration device comprises a strain box (4), the strain box (4) is in the shape of a rectangular parallelepiped as a whole, the six surfaces of the strain box (4) are composed of two mutually parallel axial surfaces, two vertical surfaces, and two horizontal surfaces, the axial surface is perpendicular to the axis of the axial stress applying head (3), the vertical surface and the horizontal surface are parallel to the axis of the axial stress applying head (3), the six surfaces of the strain box (4) are respectively provided with strain gauges (5), the outer sides of the four strain gauges (5) located on the vertical surface and the horizontal surface of the strain box (4) are respectively provided with stress gaskets (6), the outer surfaces of the stress gaskets (6) are in contact with the inner walls of the hard plastic package (2); one end of the four stress gaskets (6) extends in the direction of the axial stress applying head (3) to form a pressure head cavity, the bottom of the axial stress applying head (3) slides inside the pressure head cavity along the axial direction, and the other ends of the four stress gaskets (6) are respectively fixed to the external support assembly.

5. The three-dimensional coal body stress monitoring device for mining according to claim 4 is characterized in that: A gasket gap is provided between the four stress gaskets (6) and the side wall of the axial stress applying head (3), a strain gap is provided between the strain gauge (5) located on the axial surface of the strain box (4) and the bottom surface of the axial stress applying head (3), and the distance of the gasket gap is greater than the distance of the strain gap.

6. The three-dimensional coal body stress monitoring device for mining according to claim 5 is characterized in that: A plurality of round beads (7) are matched and arranged in the gasket gaps between the four stress gaskets (6) and the side walls of the axial stress applying head (3).

7. The three-dimensional coal body stress monitoring device for mining according to claim 4 is characterized in that: The external support assembly comprises an external support cylinder body (8), one end of the external support cylinder body (8) is a disc, the other end of the external support cylinder body (8) is a cylinder, the diameter of the disc is greater than the diameter of the cylinder, and the end surface of the disc is fixedly connected to four stress washers (6); A circular through hole is opened inside the cylindrical end of the external support cylinder body (8) along the axial direction, an external support rod (9) is coaxially sleeved in the circular through hole, a sliding gap is provided between the external support rod (9) and the disc end of the external support cylinder body (8), a plurality of groups of reserved holes (10) are distributed at intervals along the length direction on the side wall of the cylindrical end of the external support cylinder body (8), the opening direction of the reserved holes (10) is perpendicular to the axis of the cylindrical end of the external support cylinder body (8), a plurality of groups of external support bones (11) are distributed at intervals along the length direction on the side wall of the external support rod (9), one end of the external support bone (11) is hinged to the side wall of the external support rod (9), and the other end of the external support bone (11) passes through the reserved hole (10) and is hinged to the external support gasket (12).

8. The three-dimensional coal body stress monitoring device for mining according to claim 7 is characterized in that: The number of the external support bones (11) corresponds to the number of the reserved holes (10).

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