A coal seam borehole stress monitoring device

Abstract

The application discloses a coal seam drilling stress monitoring device, which comprises a drilling stress meter, a three-dimensional angle sensor and a connecting assembly with a closed positioning cavity. One end of the connecting assembly is fixedly connected with the coaxially nested drilling stress meter by magnetic attraction. The connecting assembly and the drilling stress meter can be separated. The drilling stress meter only needs to be left in the drilling hole, and the three-dimensional angle sensor can be pulled out of the drilling hole together with the connecting assembly, so that the monitoring cost is lower. The three-dimensional angle sensor is horizontally fixed in the positioning cavity. The whole push rod only needs to directly push the connecting assembly provided with the drilling stress meter to the specified position of the coal seam drilling hole, so that the problem of inaccurate monitoring caused by the threaded connection of multiple push rods is solved, and the monitoring is more accurate. Therefore, the coal seam drilling stress monitoring device can accurately and low-costly monitor the coal seam drilling.

Description

Technical Field

[0001] This invention relates to the field of coal seam stress monitoring technology, and in particular to a coal seam borehole stress monitoring device. Background Technology

[0002] As the depth of coal seam mining increases, the manifestation of mine pressure intensifies, and disasters such as rock bursts occur frequently. The rock burst problem is essentially a stress problem of the coal body. Real-time monitoring of the relative stress changes of the coal body through borehole stress gauges is of great guiding significance for ensuring safe production in coal mines.

[0003] Borehole stress gauges are typically hydraulic pillow-type. To monitor the changing trends of vertical stress in coal seams, the gauge must be installed horizontally inside the borehole. Existing monitoring methods have several drawbacks. For example, using threaded push rods connected section by section to insert the gauge into the borehole can result in a 1-2 degree deviation between any two adjacent push rod sections due to the threaded connection. The cumulative deviation angle of the entire push rod assembly can reach 10-20 degrees, leading to inaccurate monitoring results. Another example is directly mounting an inclination sensor onto the borehole stress gauge. After monitoring, the inclination sensor, borehole stress gauge, and communication cable are all left inside the borehole, resulting in significant waste and high monitoring costs.

[0004] Therefore, how to accurately and cost-effectively monitor coal seam boreholes is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a coal seam borehole stress monitoring device, wherein one end of the connecting component is fixed by magnetic attraction to a coaxially nested borehole stress gauge, and a three-dimensional angle sensor is horizontally fixed in the positioning cavity of the connecting component. The monitoring error is small, and only the borehole stress gauge needs to be left alone in the coal seam borehole. Therefore, it can accurately and cost-effectively monitor the coal seam borehole.

[0006] The coal seam borehole stress monitoring device provided by the present invention includes a borehole stress gauge, a three-dimensional angle sensor, and a connecting component with a closed positioning cavity. One end of the connecting component is fixedly connected to the coaxially nested borehole stress gauge by magnetic attraction; the three-dimensional angle sensor is horizontally fixed inside the positioning cavity.

[0007] Preferably, the connecting assembly includes a connecting housing with a positioning groove and a first positioning block and a second positioning block coaxially fixed in the positioning groove, with both ends of the three-dimensional angle sensor being fixedly connected to the first positioning block and the second positioning block, respectively.

[0008] Preferably, it also includes a cable connector fixedly connected to the connecting component and a circuit board equipped with a three-dimensional angle sensor. The first positioning block has a first locking groove, the second positioning block has a second locking groove, the circuit board is horizontally fixed between the first locking groove and the second locking groove, and the lead wire of the circuit board passes through the wire hole of the first positioning block and is connected to the cable connector.

[0009] Preferably, the connecting assembly further includes a sealing ring disposed between the first positioning block and the connecting housing.

[0010] Preferably, the connecting housing has a slot for inserting a borehole stress gauge, and a fixing magnet for adsorbing and fixing the borehole stress gauge is fixed at the bottom of the slot.

[0011] Preferably, the side wall of the slot is provided with a locking screw that abuts against the fixing magnet.

[0012] Preferably, it also includes a push rod and an adapter sleeve fixed between the push rod and the connecting assembly.

[0013] Preferably, it also includes at least one fastening screw that passes radially through the adapter sleeve and the connecting housing and is connected to the first positioning block.

[0014] Preferably, the adapter sleeve has a limiting step surface for abutting against the connecting housing along the axial direction, and also includes a sealing gasket sleeved on the cable connector and located between the limiting step surface and the connecting housing.

[0015] Preferably, it also includes an external display and a wireless communication module located within the connection assembly and connected to the three-dimensional angle sensor, wherein the monitoring signal of the three-dimensional angle sensor is transmitted to the external display through the wireless communication module.

[0016] Compared with the prior art, the coal seam borehole stress monitoring device provided by the present invention includes a cable connector, a borehole stress gauge, a three-dimensional angle sensor and a connecting assembly. The borehole stress gauge is coaxially nested at the other end of the connecting assembly, and the three-dimensional angle sensor is horizontally fixed in the positioning cavity of the connecting assembly.

[0017] The three-dimensional angle sensor is directly mounted horizontally in a closed positioning cavity. During monitoring, the entire push rod only needs to push the connecting assembly containing the borehole stress gauge directly to the designated position of the coal seam borehole. The three-dimensional angle sensor can always maintain a horizontal state to detect the stress of the coal seam borehole. The change in the installation method of the three-dimensional angle sensor eliminates the need for push rods that are connected section by section with threads, solving the problem of inaccurate monitoring caused by multiple push rods with threaded connections, and the monitoring results are naturally more accurate.

[0018] In addition, the borehole stress gauge is fixed to the connecting component by magnetic attraction. After the monitoring is completed, the connecting component can be lifted to separate the connecting component from the borehole stress gauge, leaving only the borehole stress gauge inside the borehole. The three-dimensional angle sensor can be pulled out of the borehole along with the connecting component, which helps to reduce monitoring costs.

[0019] Therefore, the coal seam borehole stress monitoring device provided by the present invention can accurately and cost-effectively monitor coal seam boreholes. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a structural diagram of the coal seam borehole stress monitoring device provided in the first specific embodiment of the present invention;

[0022] Figure 2 for Figure 1 Assembly diagram of the remaining components after removing the external display;

[0023] Figure 3 for Figure 2 A sectional view;

[0024] Figure 4 for Figure 1 A cross-sectional view of the connecting components and their accessories;

[0025] Figure 5 This is a structural diagram of the coal seam borehole stress monitoring device provided in the second specific embodiment of the present invention.

[0026] The attached figures are labeled as follows:

[0027] 1. External display; 2. Push rod; 3. Connecting bolt; 4. Adapter sleeve; 5. Cable connector; 6. Sealing gasket; 7. Connecting assembly; 8. Fastening screw; 9. Circuit board; 10. Drilling stress gauge.

[0028] Positioning cavity 71, connecting housing 72, first positioning block 73, second positioning block 74, sealing ring 75, fixing magnet 76, and locking screw 77;

[0029] Card cancellation 101. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Please refer to Figures 1 to 4 , Figure 1 This is a structural diagram of the coal seam borehole stress monitoring device provided in the first specific embodiment of the present invention; Figure 2 for Figure 1 Assembly diagram of the remaining components after removing the external display; Figure 3 for Figure 2 A sectional view; Figure 4 for Figure 1 A cross-sectional view of the connecting components and their accessories.

[0033] This invention discloses a coal seam borehole stress monitoring device, including a borehole stress gauge 10, a three-dimensional angle sensor, and a connecting assembly 7. Specifically, the borehole stress gauge 10 is a hydraulic pillow-type stress gauge, and its structure and working principle can be found in existing technologies. The three-dimensional angle sensor can be used to convert gravitational acceleration and angular velocity into pitch and roll angle values; its structure and working principle can also be found in existing technologies.

[0034] The connecting assembly 7 has a closed positioning cavity 71. The three-dimensional angle sensor is directly installed in the closed positioning cavity 71 in a horizontal state. The fixing method of the three-dimensional angle sensor can be referred to the following. During monitoring, the entire push rod 2 only needs to push the connecting assembly 7, which is equipped with the borehole stress gauge 10, directly to the designated position of the coal seam borehole. The three-dimensional angle sensor can always maintain a horizontal state to detect the stress of the coal seam borehole. The change in the installation method of the three-dimensional angle sensor eliminates the need for the push rod 2 with its sections connected by threads, thus eliminating the large angle deviation accumulated by the threaded connection of multiple push rods 2. This solves the problem of inaccurate monitoring caused by multiple threaded push rods 2, and the monitoring results are naturally more accurate.

[0035] The borehole stress gauge 10 is coaxially nested at one end of the connecting component 7. The borehole stress gauge 10 is fixed to the connecting component 7 by magnetic attraction. After the monitoring is completed, the connecting component 7 can be lifted by force to separate the connecting component 7 from the borehole stress gauge 10, leaving only the borehole stress gauge 10 inside the borehole. The three-dimensional angle sensor can be pulled out of the borehole along with the connecting component 7, which helps to reduce the monitoring cost.

[0036] In summary, the coal seam borehole stress monitoring device provided by this invention can accurately and cost-effectively monitor coal seam boreholes.

[0037] The connecting assembly 7 includes a connecting housing 72, a first positioning block 73, and a second positioning block 74. The connecting housing 72 has a positioning groove at its center. The two ends of the three-dimensional angle sensor are fixedly connected to the first positioning block 73 and the second positioning block 74, respectively. The first positioning block 73 and the second positioning block 74 are both coaxially fixed in the positioning groove. The end face of the first positioning block 73, the side wall of the positioning groove, and the end face of the second positioning block 74 can form a closed positioning cavity 71, so that the three-dimensional angle sensor can be fixed in the positioning cavity 71.

[0038] The coal seam borehole stress monitoring device provided in this embodiment of the invention further includes a cable connector 5 and a circuit board 9. A first positioning block 73 is fixed at the opening of the positioning groove. A wire-passing hole is provided at the center of the first positioning block 73. The cable connector 5 is detachably connected to the wire-passing hole of the first positioning block 73, so that the lead wire of the circuit board 9 passes through the wire-passing hole and connects to the cable connector 5. The cable connector 5 and the wire-passing hole can be connected by a thread, but the connection method is not limited to this. A second positioning block 74 is installed at the bottom of the positioning groove.

[0039] Cable connector 5 is fixedly connected to one end of connecting component 7. In a first specific embodiment, a metal cable is connected to the end of cable connector 5 away from connecting component 7, and the other end of cable connector 5 is connected to circuit board 9 equipped with a three-dimensional angle sensor. Circuit board 9 and external display 1 transmit signals via a communication cable, allowing the monitoring signal of the three-dimensional angle sensor to be transmitted to external display 1 through the metal cable. The three-dimensional angle sensor and external display 1 can use 485 communication to ensure signal anti-interference. External display 1 can be handheld and used to display the angle value fed back by the three-dimensional angle sensor for convenient data traceability. Of course, the monitoring signal of the three-dimensional angle sensor can also be transmitted wirelessly, as detailed below.

[0040] A three-dimensional angle sensor is mounted on circuit board 9. The first positioning block 73 has a first locking groove, and the second positioning block 74 has a second locking groove. Circuit board 9 is horizontally secured between the first and second locking grooves, thus horizontally fixing the three-dimensional angle sensor within the positioning cavity 71. Specifically, both the first positioning block 73 and the second positioning block 74 have elastic locking blocks glued to their ends. Each elastic locking block has an elastic groove, and each elastic groove clamps circuit board 9 using the elastic force of the material, making the circuit board 9 more reliably fixed and preventing damage to circuit board 9. It should be noted that during assembly, circuit board 9 is first fixed between the first positioning block 73 and the second positioning block 74 outside the connecting housing 72, and then the first positioning block 73, circuit board 9, and second positioning block 74 are assembled into the connecting housing 72. This ensures a tighter and more reliable connection between the three components.

[0041] A slot is provided at the end of the connecting housing 72 away from the cable connector 5, and the borehole stress gauge 10 is coaxially inserted into the slot. A fixing magnet 76 is fixed at the bottom of the slot. The fixing magnet 76 attracts and fixes the borehole stress gauge 10 by magnetic attraction, which not only allows the borehole stress gauge 10 to be inserted into the coal seam borehole together with the connecting assembly 7, but also facilitates the separation of the connecting assembly 7 and the borehole stress gauge 10.

[0042] A locking screw 77 passes through the side wall of the slot and abuts against the fixing magnet 76 radially, thereby fixing the fixing magnet 76 in the slot. Of course, the fixing method of the fixing magnet 76 is not limited to this. For example, the fixing magnet 76 can also be glued to the slot, or other similar fixing methods can be used.

[0043] The handle of the drilling stress gauge 10 is integrally provided with locking pins 101 on both opposite sides, and the two opposite sides of the slot are provided with corresponding U-shaped grooves to facilitate the drilling stress gauge 10 to avoid the locking pins 101 when it is inserted.

[0044] The coal seam borehole stress monitoring device provided in this embodiment of the invention also includes a push rod 2 and an adapter sleeve 4 fixed between the push rod 2 and the connecting assembly 7. The push rod 2 is a single rod, and one end of the adapter sleeve 4 is coaxially nested with the push rod 2. The push rod 2 and the adapter sleeve 4 are fixed together by a connecting bolt 3 that is radially through.

[0045] The other end of the adapter sleeve 4 is fitted over the connecting housing 72. The coal seam borehole stress monitoring device provided in this embodiment of the invention also includes at least one fastening screw 8. Each fastening screw 8 passes radially through the adapter sleeve 4 and the connecting housing 72 and is connected to the first positioning block 73, so that the adapter sleeve 4, the connecting housing 72 and the first positioning block 73 are fixed together. All the fastening screws 8 are evenly distributed circumferentially.

[0046] The adapter sleeve 4 has a limiting step surface inside, which abuts against the connecting housing 72 along the axial direction to axially limit the connecting housing 72. The coal seam borehole stress monitoring device provided in this embodiment of the invention also includes a sealing gasket 6 sleeved on the cable joint 5. The two ends of the sealing gasket 6 abut against the limiting step surface and the connecting housing 72 respectively, so that the cable joint 5, the adapter sleeve 4 and the connecting housing 72 have good sealing performance.

[0047] Furthermore, the connecting assembly 7 also includes a sealing ring 75 disposed between the first positioning block 73 and the connecting housing 72, ensuring good sealing between the first positioning block 73 and the connecting housing 72, preventing water from flowing into the positioning cavity 71 and affecting the service life of the circuit board 9. Specifically, the sealing ring 75 can be an O-ring rubber sealing ring 75. The combined use of the sealing gasket 6 and the sealing ring 75 enables the entire device to achieve an IP65 waterproof protection rating.

[0048] Please refer to Figure 5 , Figure 5 This is a structural diagram of the coal seam borehole stress monitoring device provided in the second specific embodiment of the present invention.

[0049] Compared to the first specific embodiment, the second specific embodiment changes the communication method between the three-dimensional angle sensor and the external display 1, while the rest of the technical solutions remain unchanged.

[0050] In a second specific embodiment, the coal seam borehole stress monitoring device provided by this invention further includes an external display 1 and a wireless communication module. The wireless communication module is located within the connecting component 7, specifically integrated on the circuit board 9. The wireless communication module is connected to a three-dimensional angle sensor, enabling the monitoring signal from the three-dimensional angle sensor to be transmitted to the external display 1 via the wireless communication module. This allows for wireless communication between the three-dimensional angle sensor and the external display 1, eliminating the cumbersome wiring process and allowing for repeated use, thus further reducing monitoring costs. Specifically, the wireless communication module can be a LoRa (Long Range Radio) communication module, employing a low-power local area network wireless standard. Under the same power consumption conditions, it can propagate farther than other wireless methods, achieving a balance between low power consumption and long distance. It can extend the distance by 3-5 times compared to traditional wireless communication modules under the same power consumption.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coal seam borehole stress monitoring device, characterized in that, The device includes a borehole stress gauge (10), a three-dimensional angle sensor, and a connecting assembly (7) with a closed positioning cavity (71). One end of the connecting assembly (7) is fixedly connected to the coaxially nested borehole stress gauge (10) by magnetic attraction. The three-dimensional angle sensor is horizontally fixed inside the positioning cavity (71). The connecting assembly (7) includes a connecting housing (72) with a positioning groove and a first positioning block (73) and a second positioning block (74) coaxially fixed in the positioning groove. The two ends of the three-dimensional angle sensor are respectively fixedly connected to the first positioning block (73) and the second positioning block (74). The coal seam borehole stress monitoring device further includes a cable connector (5) fixedly connected to the connecting component (7) and a circuit board (9) equipped with the three-dimensional angle sensor. The first positioning block (73) has a first locking groove, and the second positioning block (74) has a second locking groove. The circuit board (9) is horizontally fixed between the first locking groove and the second locking groove. The lead wire of the circuit board (9) passes through the wire hole of the first positioning block (73) and is connected to the cable connector (5).

2. The coal seam borehole stress monitoring device according to claim 1, characterized in that, The connecting assembly (7) further includes a sealing ring (75) disposed between the first positioning block (73) and the connecting housing (72).

3. The coal seam borehole stress monitoring device according to claim 1, characterized in that, The connecting housing (72) has a slot for inserting the borehole stress gauge (10), and a fixing magnet (76) for adsorbing and fixing the borehole stress gauge (10) is fixed at the bottom of the slot.

4. The coal seam borehole stress monitoring device according to claim 3, characterized in that, The side wall of the slot is provided with a locking screw (77) that abuts against the fixing magnet (76).

5. The coal seam borehole stress monitoring device according to any one of claims 1 to 4, characterized in that, It also includes a push rod (2) and an adapter sleeve (4) fixed between the push rod (2) and the connecting assembly (7).

6. The coal seam borehole stress monitoring device according to claim 5, characterized in that, It also includes at least one fastening screw (8) that passes radially through the adapter sleeve (4) and the connecting housing (72) and is connected to the first positioning block (73).

7. The coal seam borehole stress monitoring device according to claim 5, characterized in that, The adapter sleeve (4) is provided with a limiting step surface for abutting against the connecting housing (72) along the axial direction, and also includes a sealing gasket (6) sleeved on the cable connector (5) and located between the limiting step surface and the connecting housing (72).

8. The coal seam borehole stress monitoring device according to any one of claims 1 to 4, characterized in that, It also includes an external display (1) and a wireless communication module located in the connection component (7) and connected to the three-dimensional angle sensor. The monitoring signal of the three-dimensional angle sensor is transmitted to the external display (1) through the wireless communication module.

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