Mining optical fiber strain sensor

Abstract

The utility model discloses a mining optical fiber strain sensor which comprises two fixed cylinder seats, a strain detection grating unit is fixedly installed between the two fixed cylinder seats, optical fiber taps are fixedly installed at the two ends of the strain detection grating unit, and a protective cylinder is fixedly arranged at one end of each fixed cylinder seat. According to the mining optical fiber strain sensor, the stainless steel shell structural design is adopted, the mining optical fiber strain sensor can be directly buried in a concrete structure of a mine to sense strain, the sealing effect is good, the mining optical fiber strain sensor adapts to various severe corrosion environments, the overall structural strength is high, and the service life of the mining optical fiber strain sensor is prolonged. The device has the characteristics of high precision, good stability and convenience and rapidness in installation; the two ends of the sensor are packaged through the end cover assemblies, and due to the unique structural design, the two adjacent sensors can be quickly assembled in series and laid in a mine, and multi-point data acquisition can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber strain sensors, in particular to an optical fiber strain sensor for mining. Background Art

[0002] Mining fiber optic sensors are installed inside mines. When the external environmental parameters within the mine interact with the fiber Bragg grating (FBG), characteristic parameters such as the phase, intensity, and polarization state of the light within the fiber optic cable change. By measuring the relevant parameters of the light wave, the environment within the mine can be measured. Currently, the commonly used mining fiber optic strain sensors on the market mainly consist of three parts: a measuring grating, an optical fiber cable, and a digital display box. The measuring grating collects environmental variables, which are displayed on the digital display box. However, these common types of fiber optic strain sensors have the following shortcomings in actual applications:

[0003] Due to the humid environment inside the mine, optical fiber strain sensors are exposed to the humid environment for a long time, are easily corroded, and have a high failure rate. At the same time, since each optical fiber strain sensor is independent of each other, an optical fiber strain sensor needs to be installed at a certain distance in the mine to perform multi-point monitoring and improve accuracy. Traditional optical fiber strain sensors cannot be quickly assembled in series. Utility Model Content

[0004] The purpose of the utility model is to provide a mining optical fiber strain sensor to solve the problems of the existing optical fiber strain sensors proposed in the above background art, such as being easily corroded, having a high failure rate, and being unable to be quickly assembled in series.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a mining optical fiber strain sensor, comprising two fixed cylinder seats, a strain detection grating unit is fixedly installed between the two fixed cylinder seats, optical fiber taps are fixedly installed at both ends of the strain detection grating unit, a protective cylinder is fixedly provided at one end of the two fixed cylinder seats, internal and external threaded sleeves are fixedly provided on the outside of the two protective cylinders, end cover assemblies are sleeved on the outside of the two fixed cylinder seats, an outer sheath is provided between the two end cover assemblies, the inner sides of the internal and external threaded sleeves are threadedly connected to a waterproof threaded joint assembly, and the outer sides of the waterproof threaded joint assembly are threadedly connected to a sealing lock nut.

[0006] Preferably, the end cover assembly includes an end sleeve, one end of the end sleeve is fixedly connected to an insert sleeve, a fixed disk is fixedly provided at the connection between the end sleeve and the insert sleeve, the outer diameter of the insert sleeve matches the inner diameter of the outer sleeve, the sealing effect is good, and it is adaptable to various harsh corrosive environments.

[0007] Preferably, a sealing gasket is sleeved on the outer side of the insert sleeve, a threaded hole is formed on the end of the end sleeve away from the insert sleeve, and the outer side of the internal and external threaded sleeves is threadedly connected to the inner side of the threaded hole.

[0008] Preferably, the waterproof threaded joint assembly includes a hexagonal lock nut, one end of the hexagonal lock nut is fixedly provided with a first threaded barrel, the other end of the hexagonal lock nut is fixedly provided with a second threaded barrel, the second threaded barrel is threadedly connected to the inner side of the inner and outer threaded sleeves, and the sealing lock nut is threadedly connected to the outer side of the first threaded barrel; it is convenient for the series assembly of the optical fiber sensor.

[0009] Preferably, the optical fiber taps are respectively arranged inside the two protective tubes; this can protect the optical fiber taps and help reduce the failure rate.

[0010] Preferably, the outer sheath is made of stainless steel; while increasing the structural strength of the sensor, it can also improve the corrosion resistance of the sensor and extend its service life.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] This mining optical fiber strain sensor adopts a stainless steel shell design and can be directly buried in the concrete structure of the mine to sense strain. It has a good sealing effect and is adaptable to various harsh corrosive environments. The overall structural strength is high, with high accuracy, good stability and easy and quick installation.

[0013] Both ends of the sensor are encapsulated by end cap assemblies. The unique structural design allows two adjacent sensors to be quickly assembled in series and laid in a mine, enabling multi-point data collection, which is conducive to improving the accuracy of data collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the disassembled structure of the optical fiber strain sensor of the utility model;

[0015] Figure 2 This is a front cross-sectional view of the optical fiber strain sensor of the present utility model;

[0016] Figure 3 This is a front cross-sectional view of the fixed cylinder seat of the utility model;

[0017] Figure 4 This is a schematic structural diagram of a waterproof threaded joint assembly of the utility model.

[0018] In the figure: 1. Fixed cylinder seat; 2. Strain detection grating unit; 3. Internal and external threaded sleeves; 4. Protective cylinder; 5. Optical fiber tap; 6. Waterproof threaded connector assembly; 61. Hexagonal lock nut; 62. First threaded cylinder; 63. Second threaded cylinder; 7. Sealing lock nut; 8. Outer sheath; 9. Fixed disk; 10. Insert sleeve; 11. Sealing gasket; 12. End sleeve; 13. Threaded hole. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0020] See also Figure 1-4 The utility model provides a mining optical fiber strain sensor, comprising two fixed cylinder seats 1, a strain detection grating unit 2 is fixedly installed between the two fixed cylinder seats 1, optical fiber taps 5 are fixedly installed at both ends of the strain detection grating unit 2, one end of the two fixed cylinder seats 1 is fixedly provided with a protective cylinder 4, the outer sides of the two protective cylinders 4 are fixedly provided with internal and external threaded sleeves 3, the outer sides of the two fixed cylinder seats 1 are sleeved with end cover assemblies, an outer sheath 8 is provided between the two end cover assemblies, the inner sides of the internal and external threaded sleeves 3 are threadedly connected with a waterproof threaded joint assembly 6, the outer side of the waterproof threaded joint assembly 6 is threadedly connected with a sealing lock nut 7, and the outer sheath 8 is made of stainless steel.

[0021] See Figure 1 、 Figure 2 and Figure 3 Furthermore, the end cap assembly includes an end sleeve 12, one end of the end sleeve 12 is fixedly connected to the plug sleeve 10, a fixing plate 9 is fixedly provided at the connection between the end sleeve 12 and the plug sleeve 10, the outer diameter of the plug sleeve 10 matches the inner diameter of the outer sheath 8, a sealing gasket 11 is sleeved on the outer side of the plug sleeve 10, a threaded hole 13 is opened at one end of the end sleeve 12 away from the plug sleeve 10, the outer side of the inner and outer threaded sleeves 3 is threadedly connected to the inner side of the threaded hole 13, and the optical fiber tap 5 is respectively arranged inside the two protective tubes 4;

[0022] During use, when installing the optical fiber strain sensor, first loosen and remove the sealing lock nut 7 and the waterproof threaded joint assembly 6 in sequence, and put them on the optical fiber line in the order of disassembly, insert the connector on the optical fiber line into the optical fiber tap 5, then slide the waterproof threaded joint assembly 6 and tighten it to the inner side of the internal and external threaded sleeves 3, and then tighten the sealing nut 7 on the outside of the waterproof threaded joint assembly 6 for auxiliary fixation. The other end of the sensor adopts the same connection method to realize the series use of adjacent sensors.

[0023] See Figure 1 、 Figure 3 and Figure 4Furthermore, the waterproof threaded joint assembly 6 includes a hexagonal lock nut 61, one end of the hexagonal lock nut 61 is fixedly provided with a first threaded barrel 62, the other end of the hexagonal lock nut 61 is fixedly provided with a second threaded barrel 63, the second threaded barrel 63 is threadedly connected to the inner side of the internal and external threaded sleeves 3, and the sealing lock nut 7 is threadedly connected to the outer side of the first threaded barrel 62;

[0024] When in use, the hexagonal lock nut 61, the first threaded barrel 62 and the second threaded barrel 63 are connected to facilitate the insertion of the optical fiber. The second threaded barrel 63 is fixed to the internal and external threaded sleeves 3 by threads. While being used for fixing, it also isolates and seals the plug-in part of the optical fiber tap 5. The tight sealing nut 7 is screwed on the outside of the first threaded barrel 62 to seal the lead-out optical fiber, thereby improving the sealing and packaging ability of the sensor, improving the corrosion resistance and reducing the failure rate.

[0025] When the embodiment of the present application is in use: when assembling the sensor, the outer sheath 8 is first sleeved on the outer side of the fixed cylinder seat 1, and then the plug sleeves 10 are sleeved on both ends of the outer sheath 8 to improve the sealing after packaging. The end sleeve 12 is fixed to the outer side of the inner and outer threaded sleeves 3 by screwing. After tightening and fixing, the plug sleeve 10 will be inserted into the outer sheath 8 and closely contact with the outer sheath 8 through the sealing gasket ring 11 to improve the sealing. First, loosen and remove the sealing lock nut 7 and the waterproof threaded joint assembly 6 in sequence, and sleeve them on the optical fiber line in the order of disassembly, and insert the connector on the optical fiber line into the optical fiber tap 5. Then slide the hexagonal lock nut 61, insert the second threaded barrel 63 into the inner side of the inner and outer threaded sleeves 3 and tighten and fix it. After the tight sealing nut 7 is screwed on the outer side of the first threaded barrel 62, the other end is similar. The installation is convenient and efficient, with high sensitivity and stability.

[0026] The performance and related parameters of the optical fiber strain sensor are shown in the following table:

[0027]

[0028]

[0029] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mining optical fiber strain sensor, comprising two fixed cylinder seats (1), characterized in that: A strain detection grating unit (2) is fixedly installed between the two fixed cylinder seats (1), and optical fiber taps (5) are fixedly installed at both ends of the strain detection grating unit (2). A protective cylinder (4) is fixedly provided at one end of the two fixed cylinder seats (1), and internal and external threaded sleeves (3) are fixedly provided on the outer sides of the two protective cylinders (4). An end cap assembly is sleeved on the outer sides of the two fixed cylinder seats (1), and an outer sheath (8) is provided between the two end cap assemblies. The inner sides of the internal and external threaded sleeves (3) are threadedly connected to a waterproof threaded joint assembly (6), and the outer side of the waterproof threaded joint assembly (6) is threadedly connected to a sealing lock nut (7).

2. The optical fiber strain sensor for mining according to claim 1, characterized in that: The end cover assembly comprises an end sleeve (12), one end of the end sleeve (12) is fixedly connected to an insert sleeve (10), a fixed disk (9) is fixedly provided at the connection between the end sleeve (12) and the insert sleeve (10), and the outer diameter of the insert sleeve (10) matches the inner diameter of the outer sheath (8).

3. The optical fiber strain sensor for mining according to claim 2, characterized in that: The outer side of the insert sleeve (10) is provided with a sealing ring (11), the end of the end sleeve (12) away from the insert sleeve (10) is provided with a threaded hole (13), and the outer side of the internal and external threaded sleeve (3) is threadedly connected to the inner side of the threaded hole (13).

4. The optical fiber strain sensor for mining according to claim 1, characterized in that: The waterproof threaded joint assembly (6) comprises a hexagonal lock nut (61), one end of the hexagonal lock nut (61) is fixedly provided with a first threaded barrel (62), the other end of the hexagonal lock nut (61) is fixedly provided with a second threaded barrel (63), the second threaded barrel (63) is threadedly connected to the inner side of the inner and outer threaded sleeves (3), and the sealing lock nut (7) is threadedly connected to the outer side of the first threaded barrel (62).

5. The optical fiber strain sensor for mining according to claim 1, characterized in that: The two optical fiber taps (5) are respectively arranged inside the two protective tubes (4).

6. The optical fiber strain sensor for mining according to claim 1, characterized in that: The outer sheath (8) is made of stainless steel.

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