A mine-used all-directional drilling stress monitoring sensor

Abstract

This utility model discloses a mine-use omnidirectional borehole stress monitoring sensor, including a pressure gauge, a hydraulic control valve block, a flexible pressure probe, and a capillary pressure guide tube. One end of the flexible pressure probe is connected to the hydraulic control valve block via the capillary pressure guide tube. A hand pump interface is fixedly installed on one side of the hydraulic control valve block, which is used to connect an external hand pump and pump hydraulic oil into the flexible pressure probe through the capillary pressure guide tube. The flexible pressure probe can sense pressure changes in any direction around the borehole, eliminating measurement blind spots and more realistically and comprehensively reflecting the three-dimensional stress state of deep rock masses. Its simple structure reduces the number of parts, lowers manufacturing complexity and failure rate, improves the overall sealing performance and long-term operational reliability of the system, avoids the problem of inconsistent coupling of multiple hydraulic cylinders, and improves measurement accuracy.

Description

Technical Field

[0001] This utility model relates to the field of stress monitoring equipment technology, specifically a mine-use omnidirectional borehole stress monitoring sensor. Background Technology

[0002] In coal mining, real-time monitoring of the stress state inside the surrounding rock of the roadway is a key technology for preventing disasters such as roof collapse and rockburst. Currently, stress monitoring in mine boreholes mostly uses hydraulic pillow-type stress gauges. Traditional hydraulic pillows are usually flat, two-lobed structures with a single sensing direction, effectively sensing pressure perpendicular to their surface. To measure the three-dimensional stress field, multiple (usually three) hydraulic pillows in different directions need to be installed in the borehole for combined use. This structure has the following drawbacks: 1. Directional limitations: Its design gives it a certain degree of flexibility in a specific direction (perpendicular to the board surface), but it is very rigid and difficult to deform in the direction parallel to the board surface. It can only measure the stress perpendicular to the board surface and cannot achieve 360° all-directional stress perception, which may lead to misjudgment of stress direction or incomplete data.

[0003] 2. Uneven coupling: The contact between the traditional single-axis hydraulic pillow and the borehole wall is a line or surface contact, with a limited coupling area. When the rock mass undergoes slight deformation, the sensor cannot fully detect it, resulting in low measurement sensitivity and large error.

[0004] However, multiple independent hydraulic pillows cannot guarantee uniform and omnidirectional coupling with the borehole wall, which may create blind spots in perception and affect the overall judgment of the stress state of the rock mass.

[0005] 3. Complex installation: Each hydraulic bolster can only reflect stress changes in one direction, requiring extremely high accuracy in the installation angle. Installation deviations will directly lead to distortion of measurement data.

[0006] Therefore, a special mounting rod is required to ensure the angle within the hole, the metal clamp must be vertical, and the positioning must be accurate to ensure the correct orientation, which increases the difficulty and cost of installation.

[0007] 4. Incomplete data: It is impossible to continuously and comprehensively perceive the stress distribution around the borehole in 360°, and it may not be sensitive to abnormal stress concentrations in non-principal stress directions.

[0008] Therefore, there is an urgent need for a borehole stress sensor that can achieve full-range tight coupling with the borehole wall, provide more comprehensive measurement results, and is easier to install.

[0009] Therefore, there is an urgent need for a borehole stress sensor that can achieve full-range tight coupling with the borehole wall, provide more comprehensive measurement results, and is easier to install. Utility Model Content

[0010] (a) Technical problems to be solved This invention provides a mine-use omnidirectional borehole stress monitoring sensor, which aims to solve the problems mentioned in the background art.

[0011] (II) Technical Solution To achieve the above objectives, this utility model provides the following technical solution: A mining-use omnidirectional borehole stress monitoring sensor includes a pressure gauge, a hydraulic control valve block, a flexible pressure probe, and a capillary pressure guide tube. One end of the flexible pressure probe is connected to the hydraulic control valve block via the capillary pressure guide tube. A hand pump interface is fixedly installed on one side of the hydraulic control valve block. The hand pump interface is used to connect an external hand pump and pump hydraulic oil into the flexible pressure probe through the capillary pressure guide tube. The flexible pressure probe is made of a flexible metal tube through a cold shrinking process, and its cross-section is petal-shaped.

[0012] As a preferred technical solution of this application, a shut-off valve is installed on the top of the hydraulic control valve block.

[0013] As a preferred technical solution of this application, the two ends of the flexible pressure probe are welded to form a sealed cavity.

[0014] As a preferred technical solution of this application, the flexible pressure probe is tubular with a hexagonal petal-shaped cross-section and rounded corners.

[0015] As a preferred technical solution of this application, the hydraulic control valve block is a metal block with oil passages machined inside.

[0016] (III) Beneficial Effects 1. All-round perception: The shape of the flexible pressure probe can sense pressure changes in any direction around the borehole, eliminating measurement blind spots and reflecting the three-dimensional stress state of deep rock masses more realistically and comprehensively.

[0017] 2. Simplified structure and high reliability: The traditional multi-component integrated structure is simplified into a single capsule structure, which reduces the number of parts, reduces manufacturing complexity and failure rate, and improves the overall sealing performance and long-term operational reliability of the system.

[0018] 3. Easy installation and excellent coupling: By using the diameter reduction technology, the sensor can be easily inserted into a deep hole, and then achieve uniform and tight coupling with the hole wall through hydraulic expansion, avoiding the problem of inconsistent coupling of multiple hydraulic pillows and improving measurement accuracy.

[0019] 4. Low cost and easy to promote: The simplified structure leads to a reduction in manufacturing costs, while installation and maintenance are more convenient, which is conducive to large-scale promotion and application in the mining field and improves the overall level of safety production monitoring. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of an all-around borehole stress monitoring sensor for mining applications; Figure 2 for Figure 1 Cross-sectional view of the structure at point AA.

[0021] In the picture: 1. Flexible pressure probe; 2. Capillary pressure guide tube; 3. Hydraulic control valve block; 4. Pressure gauge; 5. Hand pump interface; 6. Shut-off valve. Detailed Implementation

[0022] 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.

[0023] See Figure 1 As shown, this utility model provides a mine-use omnidirectional borehole stress monitoring sensor. The sensor includes a pressure gauge 4, a hydraulic control valve block 3, a flexible pressure probe 1, and a capillary pressure guide tube 2. One end of the flexible pressure probe 1 is connected to the hydraulic control valve block 3 via the capillary pressure guide tube 2. The hydraulic control valve block 3 is installed in the roadway. The capillary pressure guide tube 2 is a flexible metal tube with a length matching the borehole depth (e.g., 10 meters). A hand pump interface 5 is fixedly installed on one side of the hydraulic control valve block 3. The hand pump interface 5 is used to connect an external hand pump and pump hydraulic oil into the flexible pressure probe 1 through the capillary pressure guide tube 2. The flexible pressure probe 1 is a capsule structure made of flexible metal tube through a cold shrinking process. Its cross-section is petal-shaped. Its initial outer diameter is larger than the target borehole diameter, and its outer diameter after shrinking is smaller than the target borehole diameter, which facilitates insertion. After the flexible pressure probe 1 is inserted into the borehole to a predetermined depth, hydraulic oil is injected into it through an external hand pump, causing it to expand and recover from the shrinking state, and finally achieve a tight coupling with the borehole wall with 360° no dead angle.

[0024] In this embodiment, a shut-off valve 6 is installed on the top of the hydraulic control valve block 3, which is used to close the entire hydraulic system after pressurization, making it an independent closed loop, thereby maintaining stable pressure.

[0025] In this embodiment, the two ends of the flexible pressure probe 1 are welded to form a sealed cavity.

[0026] See Figure 2As shown, in this embodiment, the flexible pressure probe 1 is tubular with a hexagonal petal-shaped cross-section and rounded corners. This flexible pressure probe 1 structure can sense pressure changes in any direction around the borehole, eliminating measurement blind spots and reflecting the three-dimensional stress state of deep rock masses more realistically and comprehensively.

[0027] In this embodiment, the hydraulic control valve block 3 is a metal block with an internal oil passage for connecting the hand pump interface 5, the capillary pressure guide tube 2, and the pressure gauge 4.

[0028] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A mine-use omnidirectional borehole stress monitoring sensor, comprising a pressure gauge, characterized in that: It also includes a hydraulic control valve block, a flexible pressure probe, and a capillary pressure guide tube. One end of the flexible pressure probe is connected to the hydraulic control valve block through the capillary pressure guide tube. A hand pump interface is fixedly installed on one side of the hydraulic control valve block. The hand pump interface is used to connect an external hand pump and pump hydraulic oil into the flexible pressure probe through the capillary pressure guide tube. The flexible pressure probe is made of flexible metal tube by a cold shrinking process, and its cross-section is petal-shaped.

2. The omnidirectional borehole stress monitoring sensor for mining according to claim 1, characterized in that: A shut-off valve is installed on the top of the hydraulic control valve block.

3. The omnidirectional borehole stress monitoring sensor for mining according to claim 1, characterized in that: The flexible pressure probe has two ends welded together to form a sealed cavity.

4. The omnidirectional borehole stress monitoring sensor for mining according to claim 1, characterized in that: The flexible pressure probe is tubular with a hexagonal petal-shaped cross-section and rounded corners.

5. A mine-use omnidirectional borehole stress monitoring sensor according to claim 1, characterized in that: The hydraulic control valve block is a metal block with oil passages machined inside.

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