Mounting structure and mounting method of strain sensor

Abstract

The application provides a mounting structure and a mounting method of a strain sensor, and belongs to the field of mine monitoring, and comprises a shell with a containing cavity, wherein the shell is provided with an opening communicating with the containing cavity; a sensor is mounted in the containing cavity; the inner diameter of the cavity wall of the containing cavity is greater than the outer diameter of the sensor, so that a radial gap is formed between the outer periphery of the sensor and the cavity wall when the sensor is contained; the radial gap communicates with the external atmosphere through the opening to form a non-closed air cavity structure; in the technical scheme of the application, the radial gap is arranged between the sensor and the shell to form a non-closed air cavity structure, thereby reducing the problems of poor filling and poor coupling effect caused by air sealing in the traditional grouting installation, and the setting of the fixed assembly, the limiting structure, the force arm and other components realizes the rapid positioning, fixing and screwing installation of the sensor.

Description

Technical Field

[0001] This application relates to the field of mine monitoring technology, specifically to an installation structure and installation method for a strain sensor. Background Technology

[0002] In deep metal mining, strain sensors are often installed in boreholes in the surrounding rock to monitor the manifestation of ground pressure under complex environments such as high stress and high temperature. Existing installation methods typically use grouting to couple the sensor to the surrounding rock. This method requires specialized grouting equipment, has a complex construction process, and usually requires multiple people to work together, resulting in high installation costs and low efficiency. Furthermore, when the surrounding rock has developed fissures, the grouting effect is difficult to guarantee, leading to poor coupling between the sensor and the surrounding rock. This results in the force not being effectively transmitted to the sensor when the surrounding rock deforms, affecting the accuracy and reliability of data acquisition. Summary of the Invention

[0003] In view of the technical problems existing in the background art, this application provides an installation structure and installation method for a strain sensor, which simplifies the sensor installation process, improves installation efficiency, and achieves the coupling between the sensor and the surrounding rock.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application provide an improved strain sensor structure and a grout-free installation method, characterized by comprising: A housing having a receiving cavity, the housing having an opening communicating with the receiving cavity; The sensor is installed in the receiving cavity; in, The inner diameter of the cavity wall of the receiving cavity is larger than the outer diameter of the sensor, so that a radial gap is formed between the outer periphery of the sensor and the cavity wall when the sensor is received; The radial gap communicates with the external atmosphere through the opening to form a non-enclosed air cavity structure.

[0005] Furthermore, the mounting structure also includes a fixing component and an elastic element. The fixing component is mounted on the housing and includes an abutment part, a positioning part, and a vent hole. The abutment part abuts against the wall of the receiving cavity to fix the fixing component itself inside the housing. The positioning part is inserted into one end of the sensor, and the other end of the sensor abuts against the bottom of the receiving cavity to axially limit the sensor between the positioning part and the bottom of the receiving cavity. The vent hole is provided on the fixing component to communicate the receiving cavity with the opening, thereby maintaining the non-closed air chamber structure. The elastic element is disposed in the receiving cavity, with one end abutting against the wall of the receiving cavity and the other end abutting against the abutting part of the fixing component, so as to elastically fix the fixing component in the receiving cavity.

[0006] Furthermore, the mounting structure also includes a limiting structure. At least one limiting part is provided on the outer peripheral surface of the housing. A positioning protrusion is provided on the limiting part, and the positioning protrusion is provided with a plug hole; The connector has one end inserted into the connector hole; The limiting part is provided with a slot, and the insertion part is at least partially engaged with the slot to fix the insertion part to the limiting part.

[0007] Furthermore, the mounting structure also includes a lever arm, the end of which is provided with a mating groove, which engages with the plug-in part to drive the housing to rotate through the lever arm. The lever arm is hollow and open at both ends to allow a cable for connecting the sensor to pass through.

[0008] Furthermore, the mounting structure also includes a cover portion, which covers the opening end of the housing, and the cover portion has a ventilation structure to connect the receiving cavity with the outside atmosphere; The outer wall of the opening end of the housing is provided with external threads, and the inner wall of the cover is provided with internal threads. The cover is installed on the housing through the engagement of the external threads and the internal threads. The cover includes an inner shell and an outer shell, and a hollow layer is formed between the inner shell and the outer shell. The ventilation structure includes a through hole that penetrates the cover and connects the receiving cavity, the hollow layer and the outside atmosphere.

[0009] Furthermore, the positioning protrusion is provided with a through hole, through which a cable is threaded, and the cable is electrically connected to one end of the sensor.

[0010] Furthermore, the outer peripheral surface of the housing is provided with an anti-slip structure.

[0011] Secondly, embodiments of this application provide a method for installing a strain sensor, employing the aforementioned installation structure. The installation method includes the following steps: Step S1: Modify the shape of the strain sensor by fixing a metal cone to the base of the sensor and arranging multiple columns circumferentially at the end of the sensor. Step S2: Set up monitoring points and drill installation holes. Drill installation holes perpendicular to the rock wall at the selected points. The inner diameter of the installation holes is larger than the maximum outer diameter of the modified strain sensor. Step S3: Soak the cement cartridge and fill it to the bottom of the hole. After soaking and softening the cement cartridge, push it to the bottom of the installation hole. Step S4: Install the strain sensor using tooling, insert the sensor into the hollow PVC pipe, and make the column at the end of the sensor fit into the groove of the PVC pipe. Rotate the PVC pipe to transmit torque and screw the sensor into the cement cartridge that has been filled at the bottom of the hole. Step S5: Hole gap filling and coupling curing, the cement squeezed out when the sensor is screwed in is compacted along the hole wall; Step S6: Fill the holes with cement cartridges for the second time to seal them. Fill the holes with the expanded cement cartridges one by one and compact them layer by layer. Step S7: On-site data acquisition operation, electrically connect the sensor lead cable to the data acquisition instrument, and collect and record the surrounding rock micro-strain monitoring data; Step S8: Cable arrangement and protection: The sensor cables outside the hole are bundled and arranged in an orderly manner.

[0012] Furthermore, in step S4, during the process of the sensor being screwed into the cement cartridge, the radial gap formed by the inner diameter of the cavity wall being larger than the outer diameter of the sensor, and the non-closed air cavity structure formed by the radial gap communicating with the external atmosphere through the opening, allows the air originally present in the radial gap and the cavity to be discharged into the external atmosphere through the opening as the cement cartridge gradually wraps around the housing and the sensor under compression. The cement cartridge fully and densely fills the radial gap and the cavity, and is in close contact with the outer surface of the sensor.

[0013] Furthermore, in step S7, after the cement roll hydration is stable and the sensor monitoring data curve is stable, the surrounding rock micro-strain monitoring data is formally collected and recorded. In step S8, the exposed metal wire ends of the cable are tightly wrapped with insulating and waterproof tape.

[0014] The beneficial technical effects of this application are as follows: In the technical solution of this application, by setting a radial gap between the sensor and the housing to form a non-closed air cavity structure, the problems of poor filling and poor coupling effect caused by air sealing in traditional grouting installation are reduced. The setting of components such as fixing components, limiting structures, and lever arms enables rapid positioning, fixing, and screwing installation of the sensor, simplifying the installation process, reducing reliance on professional equipment and multi-person collaboration, improving installation efficiency and reducing costs. The design of the cover, anti-slip structure, and elastic components further improves the reliability of installation. Furthermore, by modifying the shape and using tooling for screwing in, the traditional grouting installation process is simplified to a screwing operation that can be completed by a single person, without the need for professional grouting equipment or multiple people to assist, reducing the complexity of installation and labor costs. The overall structural design allows the sensor to achieve tight coupling with the surrounding rock through materials such as cement cartridges, ensuring that the deformation force of the surrounding rock is effectively transmitted to the sensor, thereby ensuring the accuracy and reliability of ground pressure monitoring data in deep metal mines.

[0015] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0017] Figure 1 This is a schematic diagram of the assembly structure of the installation structure in this application; Figure 2 This is a front view schematic diagram of the installation structure of this application; Figure 3 For this application Figure 2 Schematic diagram of AA cross-section structure; Figure 4 This is a bottom view of the installation structure of this application; Figure 5 This is a three-dimensional structural diagram of the fixing components in the installation structure of this application; Figure 6 This is a top view of the fixing component of this application; Figure 7 This is a bottom view of the fixed component structure of this application; Figure 8 For this application Figure 7 Schematic diagram of the cross-sectional structure of the middle AA section; Figure 9 This is a flowchart illustrating the specific usage method of this application; Figure 10 This is a flowchart of the installation method according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 100. Installation structure; 1. Housing; 11. Receiving cavity; 12. Limiting part; 13. Positioning protrusion; 14. Insertion part; 15. Insertion hole; 16. External thread; 2. Sensor; 3. Fixing assembly; 31. Abutting part; 32. Positioning part; 33. Vent hole; 4. Lever arm; 41. Docking groove; 5. Cover part; 51. Internal thread; 52. Inner shell; 53. Outer shell; 54. Hollow layer; 55. Through hole; 6. Elastic element. Detailed Implementation

[0019] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0021] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0024] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0025] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0026] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0027] In deep metal mining, strain sensors (2) are often installed in boreholes in the surrounding rock to monitor the manifestation of ground pressure under complex environments such as high stress and high temperature. Existing installation methods typically use grouting to couple the sensor (2) to the surrounding rock. This method requires specialized grouting equipment, has a complex construction process, and usually requires multiple people to work together, resulting in high installation costs and low efficiency. Furthermore, when the surrounding rock has developed fissures, the grouting effect is difficult to guarantee, leading to poor coupling between the sensor (2) and the surrounding rock. This results in the force not being effectively transmitted to the sensor (2) during rock deformation, affecting the accuracy and reliability of data acquisition. Therefore, existing technologies suffer from problems such as complex installation, low efficiency, and poor coupling.

[0028] To resolve the above technical issues, please refer to Figure 1This application provides a mounting structure 100 for a strain sensor, comprising: a housing 1 having a receiving cavity 11, the housing 1 having an opening communicating with the receiving cavity 11; and a sensor 2 mounted in the receiving cavity 11; wherein the inner diameter of the cavity wall of the receiving cavity 11 is larger than the outer diameter of the sensor 2, so that when the sensor 2 is received, a radial gap is formed between the outer periphery of the sensor 2 and the cavity wall; the radial gap communicates with the external atmosphere through the opening to form a non-closed air cavity structure.

[0029] In the technical solution of this application, by setting a radial gap between the sensor 2 and the housing 1 to form a non-closed air cavity structure, the problems of poor filling and poor coupling effect caused by air sealing in traditional grouting installation are reduced. The setting of components such as fixing component 3, limiting structure, and lever arm 4 realizes the rapid positioning, fixing and screwing installation of sensor 2, simplifies the installation process, reduces the dependence on professional equipment and multi-person collaboration, and improves installation efficiency. The combination of cover part 5, anti-slip structure and elastic element 6 further improves the reliability and stability of installation. Moreover, the overall structural design enables sensor 2 to achieve tight coupling with surrounding rock through materials such as cement rolls, so that the deformation force of surrounding rock can be effectively transmitted to sensor 2, thereby improving the accuracy and reliability of deep metal mine ground pressure monitoring data, and achieving the purpose of simplifying the installation process of sensor 2, improving installation efficiency and achieving the coupling effect between sensor 2 and surrounding rock.

[0030] Furthermore, it is worth mentioning that in a certain underground metal mine, strain sensors 2 were installed on the roof and sides of the transport roadway at the 1035m level to monitor the ground pressure of the surrounding rock during mining activities. Deep metal mines are in a complex environment with high depth, high stress, high ground temperature, high water pressure and strong corrosion. High stress in the deep mine often causes disasters such as delamination, buckling, collapse, rock burst, and large compression deformation. The lack of understanding of the characteristics of the ground pressure manifestation in the surrounding rock and the migration law of the mining-induced ground pressure during mining activities is the main reason for the occurrence of the above-mentioned disasters. Therefore, it is necessary to achieve close coupling between sensor 2 and the surrounding rock to obtain accurate and reliable ground pressure monitoring data.

[0031] However, traditional grouting installation methods suffer from airtightness, resulting in incomplete filling and poor coupling between sensor 2 and the surrounding rock. When the surrounding rock deforms, the force cannot be effectively transmitted to sensor 2, making it impossible to collect effective data and failing to meet the accuracy requirements for deep metal mine ground pressure monitoring. The technical solution described in this application utilizes a non-enclosed air cavity structure, allowing the cement cartridge to fully and densely fill the radial gaps and the receiving cavity 11 during the screwing-in process, ensuring tight coupling between sensor 2 and the surrounding rock. When the surrounding rock deforms due to mining activities, the deformation force can be continuously and rigidly transmitted to sensor 2 through the surrounding rock, cement cartridge, shell 1, and filling material in the radial gaps. This ensures the accuracy and real-time performance of deep metal mine ground pressure monitoring data, providing a reliable basis for stope structure design and mining plan formulation.

[0032] Please see Figure 3 and Figure 4 In some embodiments, the mounting structure 100 further includes a fixing component 3, which is mounted on the housing 1. The fixing component 3 includes an abutment part 31, a positioning part 32, and a vent 33. The abutment part 31 abuts against the wall of the receiving cavity 11 to fix the fixing component 3 itself inside the housing 1. The positioning part 32 is inserted into one end of the sensor 2, and the other end of the sensor 2 abuts against the bottom of the receiving cavity 11 to axially limit the sensor 2 between the positioning part 32 and the bottom of the receiving cavity 11. The vent 33 is provided on the fixing component 3 to connect the receiving cavity 11 with an opening to maintain a non-closed air chamber structure.

[0033] In this embodiment, the abutment part 31 and the positioning part 32 ensure that the sensor 2 is reliably axially positioned in the receiving cavity 11, reducing the displacement of the sensor 2 caused by the impact of the cement roll during installation; the vent 33 ensures that the inside of the receiving cavity 11 is connected to the opening of the housing 1 through the radial gap, maintaining the non-closed air cavity structure, so that air can be smoothly discharged, reducing the problem of forming a closed airbag near the fixing component 3.

[0034] Combination Figure 5 and Figure 6 The fixing method of the abutment part 31 will be explained below by way of example; For example, the abutment portion 31 can be the outer annular sidewall of the fixing component 3, which is fixed by cooperating with the cavity wall through interference fit, snap-fit ​​or threaded connection.

[0035] The positioning part 32 can be a cylindrical protrusion, a square groove, or a cross groove, etc., that matches the end of the sensor 2. The vent 33 can be a hollow area between the spoke-shaped support ribs, or it can be several through holes penetrating the fixing component 3.

[0036] In one specific embodiment, the improved sensor 2 has four cuboid posts at its end, which are used to cooperate with the grooves of the PVC pipe to transmit torque. In this embodiment, the positioning part 32 of the fixing component 3 is inserted into one end of the sensor 2, and the other end of the sensor 2 abuts against the bottom of the receiving cavity 11, thereby achieving reliable axial positioning of the sensor 2 within the housing 1.

[0037] With this setup, in the high temperature and high stress environment of deep metal mines, the coupling stability between sensor 2 and the surrounding rock directly affects the accuracy of monitoring data. In this embodiment, through the coordinated design of the contact part 31, the positioning part 32 and the vent 33 of the fixing component 3, reliable axial positioning of sensor 2 is achieved, and the air passage is unobstructed.

[0038] Combination Figures 7-8The abutment part 31 and the positioning part 32 prevent the sensor 2 from shifting due to the impact of the cement roll during installation, while the vent 33 ensures the connection between the radial gap and the external atmosphere, allowing air to be discharged smoothly and avoiding the formation of a closed airbag near the fixing component 3. This allows the cement roll to fully wrap the sensor 2 and achieve tight coupling.

[0039] Please see Figure 1 and Figure 3 In some embodiments, the mounting structure 100 further includes a limiting structure, at least one limiting part 12 disposed on the outer peripheral surface of the housing 1; a positioning protrusion 13 disposed on the limiting part 12, and the positioning protrusion 13 having an insertion hole 15; an insertion part 14, one end of which is inserted into the insertion hole 15; wherein the limiting part 12 has a slot, and the insertion part 14 is at least partially engaged in the slot to fix the insertion part 14 to the limiting part 12.

[0040] In this embodiment, a limiting structure is provided to provide a reliable mechanical connection and positioning basis for the installation structure 100 with external tools. The limiting part 12 is a partially protruding structure on the outer wall of the housing 1, which provides a mounting base for the subsequent positioning protrusion 13 and the insertion part 14, and bears the torque and axial force during the installation process. The positioning protrusion 13 is provided on the limiting part 12 and has an insertion hole 15, which provides a positioning reference and initial insertion fit for the insertion part 14. The slot on the limiting part 12 and the insertion part 14 form a stable mechanical interlock, which effectively prevents the insertion part 14 from axially dislodging or circumferentially slipping during the rotation installation process, and ensures the effective transmission of torque.

[0041] For example, the number and distribution of the limiting parts 12 can be set according to actual installation requirements, such as being uniformly or non-uniformly distributed along the circumference of the housing 1. The positioning protrusions 13 can be cylindrical, square, or other polygonal columnar or block structures. The slot can be a groove, notch, or stepped surface provided on the limiting part 12, etc., that can realize the locking function.

[0042] In one specific embodiment, the improved strain sensor 2 has four cuboid pillars at its end, and a groove is cut at each 90° interval on one end of the PVC pipe. The grooves of the PVC pipe engage with the protrusions at the end of the sensor 2 to transmit torque. In this embodiment, the coordinated design of the limiting part 12, the positioning protrusion 13, the insertion hole 15, and the insertion part 14 constitutes a stable mechanical interface, enabling the mounting structure 100 to reliably dock with external tools such as the lever arm 4, and efficiently transmit the operator's rotational torque to the housing 1.

[0043] With this setup, in deep metal mine surrounding rock monitoring, traditional grouting installation methods require 3-5 people to assist in the operation, resulting in high installation costs and low construction efficiency. This embodiment, through a reliable mechanical interface provided by a limiting structure, allows a single operator to efficiently transmit rotational torque to the housing 1, enabling the installation structure 100 to be screwed into the cement cartridge. This reduces installation complexity and labor costs, and improves construction efficiency.

[0044] Please see Figure 1 In some embodiments, the mounting structure 100 further includes a lever arm 4, the end of which is provided with a mating groove 41, which engages with the insertion part 14 to drive the housing 1 to rotate via the lever arm 4.

[0045] In this embodiment, the installation operation is further simplified by setting a lever arm 4. The lever arm 4 is an operating tool used to assist in screwing the installation structure 100 into the pre-placed cement cartridge. Its end is provided with a mating groove 41, which engages with the insertion part 14 to form a reliable circumferential lock, effectively transmitting the rotational torque applied by the operator to the lever arm 4 to the housing 1.

[0046] For example, the lever arm 4 can be a rod-shaped or tubular structure, and the material can be a metal tube (such as a steel or aluminum tube) or a high-strength engineering plastic tube. The length is set according to the drilling depth and ease of operation. The snap-fit ​​method between the mating groove 41 and the insertion part 14 is not limited to shape matching, but can also adopt other mechanical connection methods that can transmit torque, such as spline connection or polygonal shaft hole fit.

[0047] In one specific embodiment, a 2m long and 20mm diameter PVC pipe (lever arm 4) is prepared. A groove is cut at each 90° angle at one end of the pipe. The modified strain sensor 2, with its cable attached, is inserted into the hollow PVC pipe, so that the grooves of the PVC pipe and the protrusions at the end of the sensor 2 interlock. While rotating the PVC pipe, force is applied to screw it into the prepared cement cartridge. In this embodiment, the operator holds the lever arm 4, engages the mating groove 41 with the insertion part 14, and rotates the lever arm 4 to screw the housing 1 and the sensor 2 into the cement cartridge.

[0048] With this setup, in deep metal mine surrounding rock monitoring, traditional grouting installation methods require specialized grouting equipment and multiple people to assist in the operation, resulting in high installation costs and low construction efficiency. This embodiment simplifies the traditional multi-person collaborative grouting installation process into a single-person screw-in operation through the leverage of lever arm 4, significantly reducing the complexity of installation and labor costs.

[0049] Please see Figure 2 and Figure 3 In some embodiments, the mounting structure 100 further includes a cover 5, which covers the opening end of the housing 1 and has a ventilation structure to connect the receiving cavity 11 with the outside atmosphere.

[0050] In this embodiment, the opening end of the housing 1 is further protected by the cover 5. The cover 5 can prevent foreign objects such as debris, dust or damp cement cartridges from entering the receiving cavity 11 before or during installation, protecting the sensor 2 and its connecting lines from contamination or damage. At the same time, the ventilation structure on the cover 5 ensures the integrity of the non-enclosed air cavity structure.

[0051] For example, the cover 5 may be disc-shaped, conical, or other geometrically shaped, and the material may be metal (such as stainless steel or aluminum alloy) or engineering plastic (such as polycarbonate or nylon). The ventilation structure may be a through hole 55 or other structure capable of communicating the receiving cavity 11 with the outside atmosphere.

[0052] In one specific embodiment, the cover 5 is provided on the open end of the housing 1, and the cover 5 has a ventilation structure to connect the receiving cavity 11 with the outside atmosphere, maintain the non-closed air cavity structure, and allow air to be smoothly discharged through the ventilation structure.

[0053] With this setup, in the drilling environment of deep metal mines, there are damp cement cartridges and rock cuttings. If these enter the containment cavity 11, they will affect the measurement accuracy and service life of the sensor 2.

[0054] In this embodiment, the covering part 5 effectively prevents foreign objects from entering the cavity 11, ensuring the long-term stable operation of the sensor 2. At the same time, the ventilation structure ensures the integrity of the non-enclosed air cavity structure, allowing air to be discharged smoothly and avoiding the formation of a closed airbag near the opening of the housing 1. This allows the cement roll to wrap around the sensor 2 and achieve tight coupling.

[0055] Please see Figure 2 and Figure 3 In some embodiments, the outer wall of the opening end of the housing 1 is provided with an external thread 16, and the inner wall of the cover 5 is provided with an internal thread 51. The cover 5 is installed on the housing 1 by the cooperation of the internal thread 51 and the external thread 16. The cover 5 includes an inner shell 52 and an outer shell 53, with a hollow layer 54 formed between the inner shell 52 and the outer shell 53; The ventilation structure includes a through hole 55 that passes through the cover 5, which connects the receiving cavity 11, the hollow layer 54 and the outside atmosphere.

[0056] In this embodiment, the threaded connection allows for easy disassembly and installation of the cover 5, facilitating inspection, cleaning, or maintenance and replacement of the sensor 2 inside the receiving cavity 11. The hollow layer 54 absorbs the energy of axial impacts during installation, reducing the impact on the sensor 2. In the high-temperature environment of deep metal mines, the hollow layer 54 acts as insulation, helping to slow the conduction of external high temperatures into the receiving cavity 11. The through hole 55 penetrates the cover 5, connecting the receiving cavity 11, the hollow layer 54, and the external atmosphere, ensuring the integrity of the non-enclosed air cavity structure.

[0057] Please see Figure 1 In some embodiments, the positioning protrusion 13 is also provided with a through hole, through which a cable is threaded and electrically connected to one end of the sensor 2.

[0058] In this embodiment, the through hole can be a channel independently of the insertion hole 15, or it can be part of the insertion hole 15 itself. The cable is led out from the terminal block of the sensor 2, passes through the through hole, and finally connects to the external data acquisition equipment. In the humid and dusty environment of underground mines, this orderly cable arrangement helps reduce signal interruptions or failures caused by cable damage, improving the long-term reliability of the monitoring system.

[0059] Please see Figure 3 In some embodiments, the mounting structure 100 further includes an elastic member 6, which is disposed in the receiving cavity 11. One end of the elastic member 6 abuts against the wall of the receiving cavity 11, and the other end abuts against the abutting portion 31 of the fixing component 3, so as to elastically fix the fixing component 3 in the receiving cavity 11.

[0060] In this embodiment, the elastic element 6 can be a helical compression spring, or other components such as an elastic washer or rubber block that can provide elastic preload. The elastic element 6 is sleeved on the outer periphery of the positioning part 32, with one end abutting against the bottom wall of the receiving cavity 11 and the other end abutting against the lower surface of the abutting part 31 of the fixing component 3. It provides a continuous preload force towards the opening of the fixing component 3, adaptively compensating for manufacturing tolerances and absorbing impacts during installation, protecting the fixing component 3 and the sensor 2 from rigid impacts. When installing the sensor 2 in deep metal mines, the dimensions of the receiving cavity 11 may have manufacturing tolerances, and impacts or vibrations may occur during installation. The elastic preload and buffering effect of the elastic element 6 improve the reliability and fault tolerance of the installation structure.

[0061] Please see Figure 2 In some embodiments, the outer peripheral surface of the housing 1 is provided with an anti-slip structure, which includes a rib extending circumferentially along the housing 1, a groove extending axially along the housing 1, or a rough texture evenly distributed on the outer peripheral surface of the housing 1.

[0062] In this embodiment, by setting an anti-slip structure on the outer peripheral surface of the housing 1, the friction and mechanical engagement between the housing 1 and the cured cement cartridge are enhanced, preventing the housing 1 from rotating or axially sliding relative to the borehole wall when the surrounding rock deforms or is subjected to vibration, thereby improving the stability of the installation and the reliability of long-term monitoring.

[0063] For example, the anti-slip structure can be a raised rib extending circumferentially along the shell 1, with one or more annular raised rings, forming an annular groove when the shell 1 is screwed into the cement cartridge, and a mechanical interlock is formed between the raised rib and the groove after curing; it can also be a groove extending axially along the shell 1, so that the cured cement cartridge can be embedded to form an axial keyway fit; or it can be a rough texture evenly distributed on the outer circumference of the shell 1, formed by sandblasting, etching or knurling, which greatly increases the coefficient of friction.

[0064] In one specific embodiment, the outer peripheral surface of the housing 1 is provided with an anti-slip structure. When the housing 1 is screwed into the cement cartridge, the anti-slip structure enhances the friction and mechanical engagement between the housing 1 and the cured cement cartridge.

[0065] With this setup, during long-term monitoring of deep metal mines, the surrounding rock may deform, and there are complex working conditions such as blasting vibration and equipment operation vibration in the mine. This embodiment establishes additional mechanical constraints and frictional resistance between the shell 1 and the solidified filling material through an anti-slip structure, ensuring that the shell 1 moves synchronously with the cement cartridge, and avoiding force transmission failure or sensor 2 measurement reference drift caused by relative sliding of the shell 1.

[0066] Please see Figure 1 In some embodiments, the lever arm 4 is hollow and open at both ends to allow the cable connecting the sensor 2 to pass through.

[0067] In this embodiment, the cable of sensor 2 is led out from the open end of housing 1, passes through the hollow channel of lever arm 4, and extends from the other end to connect to external data acquisition equipment, thus realizing the integration of installation tool function and cable wiring function.

[0068] See Figure 9 and Figure 10 In one specific embodiment, a 20mm diameter PVC pipe is used. The sensor 2 cable is threaded through the hollow PVC pipe, utilizing the hollow channel of the PVC pipe to protect the cable from frictional damage. During installation in deep metal mines, rotational operations may cause the cable to rub, become entangled, or be squeezed against the borehole wall or cement cartridges. The hollow channel of the lever arm 4 provides a protective passage for the cable throughout its length, effectively reducing cable damage and improving the reliability of signal transmission. In a horizontal stage transport roadway of an underground metal mine, it is necessary to monitor the characteristics of ground pressure manifestations in the roof and sidewalls during mining activities. The specific installation steps are as follows: Step S100: Modification of the strain sensor's shape. This is described here based on the installation structure disclosed in the foregoing embodiments. In this application, the metal cone fixed to the base serves to guide, position, and increase pressure, facilitating the smooth insertion of the sensor into the cement cartridge, while simultaneously increasing the contact area between the sensor and the filling medium. The cuboid column arranged circumferentially at the end can cooperate with external tooling to achieve torque transmission, enabling the sensor 2 to be screwed in and installed.

[0069] Step S200: Select monitoring points and drill installation holes. Based on the layout of the underground mining project and the needs of surrounding rock monitoring, select monitoring points. Use rock drilling equipment to drill installation holes perpendicular to the rock wall at the selected points. The depth of the installation holes is set to 1m, and the inner diameter of the installation holes is larger than the maximum outer diameter of the modified strain sensor. The specific models of rock drilling equipment and strain sensors can be flexibly selected according to the existing equipment conditions at the mine site. The selected points are selected based on the needs of on-site monitoring tasks, disaster prevention and control and ground pressure analysis. Points are preferentially placed in the surrounding rock areas of roadways where mining disturbances are significant. The number and location of points can be flexibly adjusted according to actual monitoring needs.

[0070] Step S300: Soak the cement cartridge and fill it to the bottom of the hole. Select a cement cartridge of appropriate specifications and completely immerse it in clean water. After soaking, knead the cartridge to confirm that it has softened. Use a feeding stick to push the soaked cement cartridge to the bottom of the installation hole. The soaking time of the cement cartridge is determined according to its product model and instructions for use. The total length of the cement cartridge filled to the bottom of the hole should be controlled to be twice the overall length of the modified strain sensor to ensure that the bottom of the sensor is fully wrapped and coupled by the medium.

[0071] Step S400: Install the strain sensor using a tooling fixture. Select a hollow PVC pipe as the installation fixture. Make grooves at 90° intervals along the circumference on one end of the PVC pipe wall, matching the cuboid post at the end of the sensor. Insert the end of the strain sensor with the cable into the PVC pipe, causing the cuboid post at the end of the sensor 2 to engage in the groove of the PVC pipe, achieving circumferential locking. Holding the end of the PVC pipe away from the groove, rotate the PVC pipe to transmit torque while applying axial thrust, screwing the entire strain sensor 2 into the cement cartridge already filled at the bottom of the hole. The outer diameter of the selected PVC pipe is smaller than the maximum outer diameter of the strain sensor 2, and the inner diameter is larger than the outer diameter of the sensor cable to avoid jamming during installation.

[0072] During this screwing-in process, because the inner diameter of the cavity wall is larger than the outer diameter of the sensor, a radial gap is formed between them, and this gap communicates with the outside atmosphere through the opening of the housing. When the housing is screwed into the cement cartridge, the cement cartridge gradually wraps around the housing under compression. The air that was originally present in the radial gap and the cavity under compression can be smoothly discharged to the outside atmosphere through the opening, instead of being trapped between the housing and the sensor to form an air pocket. When the surrounding rock deforms, the deformation force can be effectively transmitted to the sensor through the surrounding rock and the cement cartridge, thereby ensuring that the sensor can accurately sense and collect the strain data of the surrounding rock, achieving tight coupling between the sensor and the surrounding rock. This non-enclosed air cavity structure reduces coupling failure caused by air retention, improving the reliability of installation and the accuracy of monitoring data.

[0073] Step S500: Hole Gap Filling and Coupling Curing. After the modified strain sensor is fully screwed into the pre-filled cement cartridge at the bottom of the hole and its positioning is stable, the borehole gap filling operation is carried out. A thin wooden stick is used to compact the cement squeezed out during the sensor insertion along the hole wall 360°, eliminating all voids around the sensor. The cement cartridge undergoes a hydration reaction upon contact with water and produces a micro-expansion effect. After hardening, it tightly wraps around the sensor, eliminating the slippage gap between the sensor and the surrounding rock borehole wall, forming a rigid force transmission medium layer. This ensures that stress can be completely transmitted to the strain sensor when the surrounding rock undergoes micro-deformation, improving the effectiveness of monitoring data acquisition.

[0074] Step S600: Secondary filling of cement cartridges to complete hole sealing. Take another cement cartridge and immerse it completely in water until softened. Use a feeding stick to fill the installed holes with the softened cement cartridges one by one, compacting each layer.

[0075] Step S700: On-site data acquisition operation. Connect the sensor lead cable to the data acquisition instrument electrically. Power on and check the signal transmission status to confirm that the equipment communication is normal. Since the cement hydration reaction is accompanied by heat generation and volume expansion, after installation, it can be moved to the next monitoring point for construction. After the cement hydration is stable and the sensor monitoring data curve is stable without significant fluctuations, formally collect and record the surrounding rock micro-strain monitoring data.

[0076] Step S800: Cable arrangement and protection. After the monitoring operation is completed, the sensor cables outside the hole are bundled and arranged in an orderly manner. The exposed metal wire ends of the cables are tightly wrapped with insulating and waterproof tape to isolate them from the damp and corrosive environment underground, prevent the lines from rusting and short circuits, and extend the service life of the equipment.

[0077] As can be seen from the above application examples, this application simplifies the traditional complex grouting installation process into a single-person screw-in operation, eliminating the need for specialized grouting equipment and multiple assistants. This reduces the complexity of installation and labor costs, and improves construction efficiency. At the same time, through the non-enclosed air chamber structure, the positioning and ventilation design of the fixed components, and the convenient operation of the lever arm, it reduces the technical problems of incomplete filling and poor coupling effect caused by air sealing. This allows the sensor to achieve tight coupling with the surrounding rock through the cement cartridge, thereby improving the accuracy and reliability of ground pressure monitoring data in deep metal mines.

[0078] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A mounting structure for a strain sensor, characterized in that, include: A housing having a receiving cavity, the housing having an opening communicating with the receiving cavity; The sensor is installed in the receiving cavity; in, The inner diameter of the cavity wall of the receiving cavity is larger than the outer diameter of the sensor, so that a radial gap is formed between the outer periphery of the sensor and the cavity wall when the sensor is received; The radial gap communicates with the external atmosphere through the opening to form a non-enclosed air cavity structure.

2. The mounting structure of the strain sensor according to claim 1, characterized in that, The mounting structure further includes a fixing component and an elastic element. The fixing component is mounted on the housing and includes an abutment part, a positioning part, and a vent. The abutment part abuts against the wall of the receiving cavity to fix the fixing component itself inside the housing. The positioning part is inserted into one end of the sensor, and the other end of the sensor abuts against the bottom of the receiving cavity to axially limit the sensor between the positioning part and the bottom of the receiving cavity. The vent is provided on the fixing component to connect the receiving cavity with the opening, thereby maintaining the non-closed air chamber structure. The elastic element is disposed in the receiving cavity, with one end abutting against the wall of the receiving cavity and the other end abutting against the abutting part of the fixing component, so as to elastically fix the fixing component in the receiving cavity.

3. The mounting structure of the strain sensor according to claim 1, characterized in that, The mounting structure also includes a limiting structure. At least one limiting part is disposed on the outer peripheral surface of the housing; A positioning protrusion is provided on the limiting part, and the positioning protrusion is provided with a plug hole; The connector has one end inserted into the connector hole; The limiting part is provided with a slot, and the insertion part is at least partially engaged with the slot to fix the insertion part to the limiting part.

4. The mounting structure of the strain sensor according to claim 3, characterized in that, The mounting structure also includes a lever arm, the end of which is provided with a mating groove. The mating groove engages with the plug-in part to drive the housing to rotate. The lever arm is hollow and open at both ends to allow a cable connecting the sensor to pass through.

5. The mounting structure of the strain sensor according to claim 1, characterized in that, The mounting structure also includes a cover portion, which covers the opening end of the housing, and the cover portion has a ventilation structure to connect the receiving cavity with the outside atmosphere; The outer wall of the opening end of the housing is provided with external threads, and the inner wall of the cover is provided with internal threads. The cover is installed on the housing through the engagement of the external threads and the internal threads. The cover includes an inner shell and an outer shell, and a hollow layer is formed between the inner shell and the outer shell. The ventilation structure includes a through hole that penetrates the cover and connects the receiving cavity, the hollow layer and the outside atmosphere.

6. The mounting structure of the strain sensor according to claim 5, characterized in that, The positioning protrusion is also provided with a through hole, and a cable is inserted through the through hole. The cable is electrically connected to one end of the sensor.

7. The mounting structure of the strain sensor according to claim 3, characterized in that, The outer circumferential surface of the shell is provided with an anti-slip structure.

8. A method for installing a strain sensor, characterized in that, The installation method, employing the installation structure as described in any one of claims 1 to 7, comprises the following steps: Step S100: Modify the shape of the strain sensor by fixing a metal cone to the base of the sensor and arranging multiple columns circumferentially at the end of the sensor. Step S200: Set up monitoring points and drill installation holes. Drill installation holes perpendicular to the rock wall at the selected points. The inner diameter of the installation holes is larger than the maximum outer diameter of the modified strain sensor. Step S300: Soak the cement cartridge and fill it to the bottom of the hole. After soaking and softening the cement cartridge, push it to the bottom of the installation hole. Step S400: Install the strain sensor using tooling, insert the sensor into the hollow PVC pipe, and make the column at the end of the sensor fit into the groove of the PVC pipe. Rotate the PVC pipe to transmit torque and screw the sensor into the cement cartridge that has been filled at the bottom of the hole. Step S500: Hole gap filling and coupling curing, the cement squeezed out when the sensor is screwed in is compacted along the hole wall; Step S600: Complete the sealing of the hole by filling the cement cartridges with cement for the second time. Fill the installation hole with the expanded cement cartridges in sequence and compact them layer by layer. Step S700: On-site data acquisition operation, electrically connect the sensor lead cable to the data acquisition instrument, and collect and record the surrounding rock micro-strain monitoring data; Step S800: Cable arrangement and protection treatment, the sensor cables outside the hole are bundled and arranged in an orderly manner.

9. The installation method according to claim 8, characterized in that, In step S400, during the process of the sensor being screwed into the cement cartridge, the radial gap formed by the inner diameter of the cavity wall being larger than the outer diameter of the sensor, and the non-closed air cavity structure formed by the radial gap communicating with the outside atmosphere through the opening, allows the air originally present in the radial gap and the cavity to be discharged to the outside atmosphere through the opening as the cement cartridge gradually wraps around the housing and the sensor under compression. The cement cartridge fully and densely fills the radial gap and the cavity, and is in close contact with the outer surface of the sensor.

10. The installation method according to claim 8, characterized in that, In step S700, after the cement hydration of the molten cement roll is stable and the sensor monitoring data curve is stable, the surrounding rock micro-strain monitoring data is formally collected and recorded. In step S800, the exposed metal wire ends of the cable are tightly wrapped with insulating and waterproof tape.

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