Mining borehole stress monitoring device

Abstract

The utility model belongs to the technical field of coal mine stress detection, and particularly relates to a mining drill hole stress monitoring device which comprises a cylinder body, and a power mechanism and a detection mechanism are arranged on the cylinder body. Compared with a traditional stress monitoring device in which liquid is injected into a flexible rubber pipe, the mining borehole stress monitoring device is used for pushing the conical block to enable the rubber pipe to expand and be attached to the hole wall during installation, and pressure is no longer transmitted through hydraulic oil after installation is completed; meanwhile, the two sets of strain sensors with the included angle of 90 degrees are arranged on the outer wall of the rubber pipe, the stress in the vertical direction and the stress in the horizontal direction can be detected respectively, and the stability and reliability of the device in long-term use are greatly improved. Compared with a common device which can only measure stress perpendicular to the surface of the sensor, the device can more comprehensively obtain borehole stress information, and more accurate stress data are provided for projects such as coal mining.

Description

Technical Field

[0001] This utility model relates to the field of coal mine stress detection technology, specifically a mine borehole stress monitoring device. Background Technology

[0002] The coal mining process causes the weight and stress of the rock strata and coal seams to be redistributed to the unmined coal seams, and this redistribution can exhibit certain patterns. The pattern of stress change in the coal body can guide the support design of roadways and longwall faces.

[0003] Currently, existing stress monitoring devices developed to meet this need primarily involve drilling holes in the coal seam and placing stress sensors inside. As mining progresses, the stress in the coal seam increases, applying pressure to the sensors, which then indirectly provide stress values. There are three common types: one uses a flexible rubber tube filled with pressurized oil or other liquid, but this is susceptible to rubber corrosion and leakage; the second uses a circular support with resistive strain gauges, offering high accuracy but requiring cable for signal transmission, which is easily damaged by pressure, and the sensors are expensive; the third is a flat, strip-shaped cavity made of metal, connected by a high-pressure alloy tube and filled with hydraulic oil. This method is the most common, but it can only measure stress perpendicular to the sensor surface. Therefore, we propose a mine borehole stress monitoring device. Utility Model Content

[0004] The main objective of this invention is to provide a stress monitoring device for mine boreholes that can solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model proposes a mining borehole stress monitoring device, comprising a cylinder, on which a power mechanism and a detection mechanism are provided. The detection mechanism includes:

[0006] A rubber tube is connected to the end of a cylinder. A strain sensor is provided on the outer wall of the rubber tube. There are two sets of strain sensors, and the angle between the two sets of strain sensors is 90 degrees. They are used to detect the stress in the vertical and horizontal directions on the strain sensors, respectively.

[0007] A conical block, which is disposed inside the cylinder.

[0008] Preferably, the inner wall of the cylinder is connected to a partition, which divides the inner part of the cylinder into cavity a and cavity b. Cavity a is connected to a rubber tube, and the conical block is located in cavity a.

[0009] Preferably, a piston block is provided inside the cavity b, and a rod is connected to the outer wall of the piston block. The end of the rod away from the piston block is connected to a conical block.

[0010] Preferably, the side wall and bottom of the cylinder are provided with oil injection ports.

[0011] Preferably, the power mechanism includes a high-pressure oil pipe, the two ends of which are connected to the oil inlet on the side wall and the oil inlet at the bottom of the cylinder, respectively. A power pump is provided in the middle of the high-pressure oil pipe to provide power to the entire device.

[0012] Preferably, the outer wall of the partition is connected to a crossbar, which passes through the conical block and is slidably connected to the conical block.

[0013] Preferably, the partition plate is provided with a sealing ring to improve the sealing performance of cavity a and prevent hydraulic oil from entering the interior of cavity a.

[0014] This utility model provides a stress monitoring device for mine boreholes. It has the following beneficial effects:

[0015] (1) This mining borehole stress monitoring device differs from traditional stress monitoring devices that use flexible rubber tubes with internal liquid injection. During installation, this device is used to push a conical block to expand the rubber tube and fit against the borehole wall. After installation, it no longer relies on hydraulic oil to transmit pressure, avoiding the situation where the strain sensor loses pressure due to rubber corrosion or liquid leakage. This greatly improves the stability and reliability of the device in long-term use. At the same time, two sets of strain sensors with an included angle of 90 degrees are set on the outer wall of the rubber tube, which can detect stress in the vertical and horizontal directions respectively. Compared with common devices that can only measure stress perpendicular to the sensor surface, this device can obtain more comprehensive borehole stress information and provide more accurate stress data for coal mining and other projects.

[0016] (2) The mining borehole stress monitoring device can move the piston block by reversing the start of the power pump, which will drive the conical block back to its original position, thus realizing the recycling and reuse of the device and reducing the cost of use. In addition, during the recycling process, the crossbar is cleverly designed to abut against the top of the rubber tube, preventing the rubber tube from being carried into the cylinder by the conical block under the action of friction, avoiding damage to the rubber tube due to improper operation, extending the service life of the rubber tube, and ensuring the safety and stability of the device during the recycling process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0019] Figure 2 This is a schematic diagram of a partial three-dimensional cross-sectional structure of the present invention. Figure 1 ;

[0020] Figure 3 This is a schematic diagram of a partial three-dimensional cross-sectional structure of the present invention. Figure 2 ;

[0021] Figure 4 This utility model Figure 3 Schematic diagram of structure A in the middle.

[0022] Explanation of icon numbers:

[0023] 1. Cylinder body; 10. Oil inlet; 11. Baffle plate; 12. Conical block; 13. Crossbar; 14. Rod body; 15. Piston block; 16. Sealing ring; 2. Rubber hose; 3. Strain sensor; 4. High-pressure oil pipe; 5. Power pump.

[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figures 1-4 This utility model proposes a stress monitoring device for mining boreholes, including a cylinder 1, with oil inlets 10 on both the side wall and bottom of the cylinder 1, and a power mechanism and a detection mechanism on the cylinder 1.

[0027] In this embodiment of the invention, in order to detect drilling stress, the detection mechanism specifically includes a rubber tube 2 connected to the end of the cylinder 1. A strain sensor 3 is provided on the outer wall of the rubber tube 2. Two sets of strain sensors 3 are provided, with an angle of 90 degrees between them. These sensors are used to detect stress in the vertical and horizontal directions on the strain sensors 3, respectively. A conical block 12 is disposed inside the cylinder 1. A partition 11 is connected to the inner wall of the cylinder 1, dividing the interior of the cylinder 1 into a cavity a and a hollow space a. Cavity b is connected to cavity a and rubber tube 2. Conical block 12 is located in cavity a. Cavity b is provided with piston block 15. A rod 14 is connected to the outer wall of piston block 15. The end of rod 14 away from piston block 15 is connected to conical block 12. A crossbar 13 is connected to the outer wall of partition 11. The crossbar 13 passes through conical block 12 and is slidably connected to conical block 12. A sealing ring 16 is provided on partition 11 to improve the sealing of cavity a and prevent hydraulic oil from entering the interior of cavity a. High-pressure oil pipe 4 and cavity b are filled with hydraulic oil.

[0028] Furthermore, the power mechanism includes a high-pressure oil pipe 4, with both ends of the high-pressure oil pipe 4 connected to the side wall oil inlet 10 and the bottom oil inlet 10 of the cylinder 1, respectively. A power pump 5 is provided in the middle of the high-pressure oil pipe 4 to provide power to the entire device.

[0029] In this utility model, when in use, the rubber tube 2 is first inserted into the borehole, and then the power pump 5 is started. At this time, the hydraulic oil between the piston block 15 and the partition plate 11 will be injected into the space between the piston block 15 and the inner wall of the cylinder 1 through the high-pressure oil pipe 4 under the action of the power pump 5. At this time, under the thrust of the hydraulic oil, the piston block 15 moves towards the partition plate 11. At this time, the conical block 12 will be pushed into the rubber tube 2 under the thrust, causing the rubber tube 2 to expand and stick to the borehole wall together with the external strain sensor 3. At this time, the pressure value of the strain sensor 3 is read to determine whether the target pressure has been reached. If it is less than the specified pressure, the hydraulic oil is pressurized to push the conical block 12 further in and expand the rubber tube 2 until the specified pressure is reached. It should be noted that under the stress in the vertical direction of the coal body, the force converted to the axial direction of the conical block 12 is extremely small. Its frictional resistance with the rubber wall will keep it stationary. At this time, the hydraulic force in the axial direction is eliminated, which does not affect its final state. Thus, the problem of hydraulic oil leakage causing the strain sensor 3 to lose pressure after long-term use is solved.

[0030] When recycling is required, the hydraulic pump 5 is started in reverse. At this time, the hydraulic oil between the piston block 15 and the inner wall of the cylinder 1 will be injected into the space between the piston block 15 and the partition plate 11 under the action of the hydraulic pump 5. Under the thrust of the hydraulic oil, the piston block 15 will move towards the bottom of the cylinder 1. At this time, the conical block 12 will return to its original position under the action of the thrust. During this process, the crossbar 13 will abut against the top of the rubber tube 2 to prevent the rubber tube 2 from being carried into the interior of the cylinder 1 by the conical block 12 under the action of friction during the movement of the conical block 12.

[0031] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A stress monitoring device for mining boreholes, comprising a cylinder (1), wherein the cylinder (1) is provided with a power mechanism and a detection mechanism, characterized in that: The testing institutions include: A rubber tube (2) is connected to the end of the cylinder (1). A strain sensor (3) is provided on the outer wall of the rubber tube (2). There are two sets of strain sensors (3), and the angle between the strain sensors (3) and the two sets of strain sensors (3) is 90 degrees. They are used to detect the stress in the vertical and horizontal directions on the strain sensors (3). A conical block (12) is disposed inside the cylinder (1).

2. The stress monitoring device for mine boreholes according to claim 1, characterized in that: The inner wall of the cylinder (1) is connected to a partition (11), which divides the interior of the cylinder (1) into cavity a and cavity b. Cavity a is connected to the rubber tube (2), and the conical block (12) is located in cavity a.

3. The stress monitoring device for mine boreholes according to claim 2, characterized in that: A piston block (15) is provided inside the cavity b. A rod (14) is connected to the outer wall of the piston block (15). The end of the rod (14) away from the piston block (15) is connected to a conical block (12).

4. The stress monitoring device for mine boreholes according to claim 1, characterized in that: The cylinder (1) has oil inlets (10) on its side wall and bottom.

5. A mining borehole stress monitoring device according to claim 4, characterized in that: The power mechanism includes a high-pressure oil pipe (4), the two ends of which are connected to the side wall oil inlet (10) and the bottom oil inlet (10) of the cylinder (1), respectively. A power pump (5) is provided in the middle of the high-pressure oil pipe (4) to provide power to the entire device.

6. A mining borehole stress monitoring device according to claim 2, characterized in that: The outer wall of the partition (11) is connected to a crossbar (13), which passes through the conical block (12) and is slidably connected to the conical block (12).

7. A mining borehole stress monitoring device according to claim 2, characterized in that: The partition (11) is provided with a sealing ring (16) to improve the sealing of cavity a and prevent hydraulic oil from entering the cavity a.

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