Drilling stress sensor
By designing a gourd-shaped borehole stress sensor with an internally separated oil bladder and axial stress oil bladder, the problems of large hydraulic oil consumption and insufficient axial stress monitoring were solved, achieving stable and comprehensive stress monitoring results.
Patent Information
- Application Number
- CN202423041228.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-10
AI Technical Summary
Existing borehole stress gauges use a large amount of hydraulic oil, are prone to pressure drops, and lack the ability to monitor changes in axial stress.
A gourd-shaped, irregularly shaped cavity is designed as the main oil bladder, which is internally divided into two independent oil bladder cavities. Combined with the axial stress oil bladder, stable monitoring can be achieved with a small amount of hydraulic oil. It can also monitor stress changes in the borehole vertically or horizontally, and monitor axial stress changes through the axial stress oil bladder.
It reduces the amount of hydraulic oil used, ensures stable monitoring over a long period of time, and can comprehensively monitor multi-directional stress changes in the borehole, thus improving the accuracy and comprehensiveness of the monitoring data.
Smart Images
Figure CN223482648U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of stress monitoring technology in coal mine roadways, and specifically to a borehole stress sensor. Background Technology
[0002] In daily coal mining operations, the extraction of coal inevitably leads to a redistribution of the rock stress field. This new stress field distribution has a significant impact on the stability of roadways and mining areas, especially in deep mines where rockbursts frequently occur due to the high concentration of stress in the surrounding rock. Monitoring rockbursts can be directly reflected by changes in rock stress. Borehole stress gauges, as monitoring devices for stress changes in the surrounding rock of mine roadways, are widely used in current technology. Most existing borehole stress gauges use hydraulic oil conservators. A cylindrical hydraulic oil conservator is placed in the borehole and pressurized with oil to ensure full contact between the conservator and the borehole wall, allowing for real-time monitoring of stress changes. However, because the hydraulic oil conservator is cylindrical, it needs to be completely filled with hydraulic oil to function effectively, making installation and filling difficult. Furthermore, the large amount of hydraulic oil used can lead to pressure drop over long-term use, affecting the normal operation of the borehole stress gauge. In addition, existing borehole stress gauges lack the ability to monitor stress changes along the borehole axis. Summary of the Invention
[0003] To address the problems in the existing technology, this utility model patent designs a borehole stress sensor to solve the problems of large hydraulic oil consumption, easy pressure drop, and limited monitoring data in existing borehole stress gauges.
[0004] The technical solution adopted by this utility model is as follows: the main oil bladder has a non-cylindrical, irregularly shaped cavity structure. One end of the main oil bladder is fixedly connected to an angle sensor, and the other end is connected to an axial stress oil bladder. The axial stress oil bladder is connected to a third oil injection pipe, which is arranged along the axis of the main oil bladder and extends outward.
[0005] Furthermore, a partition is provided inside the main oil bladder along the axis to divide the internal cavity of the main oil bladder into two independent first oil bladder cavities and second oil bladder cavities. The oil inlet ends of the first oil bladder cavity and the second oil bladder cavities are respectively connected to a first oil injection pipe and a second oil injection pipe.
[0006] Furthermore, the partition plate has an integrally formed axial perforation at its center, and the third oil injection pipe of the axial stress oil bladder is arranged along the axial perforation of the partition plate.
[0007] Furthermore, the main oil bladder has a gourd-shaped structure, and the partition is arranged along the symmetrical center line of the gourd-shaped structure.
[0008] Furthermore, the first and second oil bladder cavities of the main oil bladder of the borehole stress sensor are arranged in the vertical direction or in the horizontal direction during application.
[0009] Furthermore, the axial stress oil bladder has an axial pleated structure, which can deform and expand along the axial direction.
[0010] Compared to existing technologies, the advancement of this borehole stress sensor design lies in the following: the main oil bladder of the borehole stress gauge is configured with a gourd-shaped, irregularly shaped cavity structure, reducing the volume of the internal cavity. During application, only a small amount of hydraulic oil is needed to pressurize the main oil bladder, ensuring stable pressure over extended periods. The interior of the main oil bladder is divided into two independent chambers, monitoring stress changes from the borehole's vertical or horizontal directions respectively, resulting in more accurate data. Furthermore, an axial stress oil bladder is located at the end of the main oil bladder. This axial stress oil bladder features a pleated structure capable of axial deformation and expansion, enabling comprehensive monitoring of stress changes along the borehole's axial direction. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the borehole stress sensor.
[0012] Figure 2 This is a schematic diagram of the cross-sectional structure of the main oil bladder of the borehole stress sensor.
[0013] In the figure, 1 is the main oil bladder, 2 is the axial stress oil bladder, 3 is the tilt sensor, 11 is the first oil bladder cavity, 12 is the second oil bladder cavity, 13 is the partition, 14 is the first oil injection pipe, 15 is the second oil injection pipe, 16 is the shaft perforation, and 21 is the third oil injection pipe. Detailed Implementation
[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0015] like Figure 1 , 2 As shown, this utility model patent designs a first embodiment of a borehole stress sensor. In this embodiment, the borehole stress sensor includes a main oil bladder 1. One end of the main oil bladder 1 is fixedly connected to an inclination sensor 3, and the other end is fixedly connected to an axial stress oil bladder 2. The inclination sensor 3 is a prior art product and is electrically connected to an external sensor through a signal line.
[0016] The main oil bladder 1 has a gourd-shaped structure. Inside the main oil bladder 1, a partition 13 is integrally formed along the symmetrical center line of the gourd-shaped structure. The partition 13 has an integrally formed axial perforation 16 along its axis. The partition 13 divides the internal cavity of the main oil bladder 1 into two independent first oil bladder cavities 11 and second oil bladder cavities 12. The oil inlet ends of the first oil bladder cavities 11 and second oil bladder cavities 12 are respectively connected to the first oil injection pipe 14 and the second oil injection pipe 15. The first oil injection pipe 14 and the second oil injection pipe 15 are respectively connected to external sensors and oil injection pumps through three-way valves.
[0017] The axial stress oil bladder 2 has an axial pleated structure, which can deform and expand along the axial direction. The oil inlet end of the axial stress oil bladder 2 is connected to a third oil injection pipe 21. The third oil injection pipe 21 is set along the axial through hole 16 of the partition 13 of the main oil bladder 1 and passes through the end of the main oil bladder 1. The third oil injection pipe 21 is also connected to the external sensor and oil injection pump through a three-way valve.
[0018] In the application of the borehole stress sensor disclosed in this utility model patent, a push rod is used to push the main oil bladder 1 and the axial stress oil bladder 2 together to the bottom of the borehole, so that the end of the axial stress oil bladder 2 abuts against the bottom of the hole. The placement posture of the main oil bladder 1 is adjusted by the value fed back by the tilt sensor 4, so that the first oil bladder cavity 11 and the second oil bladder cavity 12 of the main oil bladder 1 are vertically aligned or horizontally aligned. Then, oil is injected into the main oil bladder 1 to the rated pressure by the oil injection pump to ensure that the main oil bladder 1 is in full contact with the borehole wall. Then, oil is injected into the axial stress oil bladder 2 to the rated pressure by the oil injection pump, thus completing the installation of the borehole stress sensor.
[0019] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the present invention.
Claims
1. A borehole stress sensor, the borehole stress sensor comprising a main oil bladder, characterized in that, The main oil bladder has a non-cylindrical gourd-shaped constricted cavity structure. One end of the main oil bladder is fixedly connected to an angle sensor, and the other end is connected to an axial stress oil bladder. The axial stress oil bladder is connected to a third oil injection pipe, which is arranged along the axis of the main oil bladder and extends outward.
2. A borehole stress sensor according to claim 1, characterized in that, The main oil bladder has a partition along its axis inside, which divides the internal cavity of the main oil bladder into two independent first oil bladder cavities and second oil bladder cavities. The oil inlet ends of the first oil bladder cavity and the second oil bladder cavities are respectively connected to the first oil injection pipe and the second oil injection pipe.
3. A borehole stress sensor according to claim 2, characterized in that, The partition plate has an integrally formed axial perforation at its center, and the third oil injection pipe of the axial stress oil bladder is arranged along the axial perforation of the partition plate.
4. A borehole stress sensor according to claim 3, characterized in that, The partition is arranged along the symmetrical centerline of the gourd-shaped constricted cavity structure.
5. A borehole stress sensor according to claim 4, characterized in that, The first and second oil bladder cavities of the main oil bladder of the borehole stress sensor are arranged either vertically or horizontally during application.
6. A borehole stress sensor according to claim 1, characterized in that, The axial stress oil bladder has an axial pleated structure, which can deform and expand along the axial direction.