Fiber bragg grating measuring anchor rod

Abstract

The utility model discloses a fiber bragg grating measuring anchor rod, which is characterized in that optical fibers of grating sensors are placed in a spiral groove on a cylinder from top to bottom and are fixed on the threaded surface of the cylinder by using optical fiber fixing glue, each circle of thread is provided with at least four grating sensors, and the middle part of the cylinder is provided with a vertical hollow area with the width of 3-5mm from top to bottom; the optical fiber reaching the bottom end penetrates through the area and returns to the upper end of the column body, a connecting box is arranged at the upper end of the column body, and the optical fiber is connected with a pressure monitor in the connecting box and a demodulator outside the connecting box in parallel. The measuring anchor rod bottom optical fiber can be connected in series with other anchor rod optical fibers to form a regional measuring network, so that the measuring flexibility of equipment is improved; the pressure monitor is adopted, and real-time pressure alarm display can be achieved through the monitor.

Description

Technical Field

[0001] The utility model relates to the technical field of measurement engineering, in particular to a fiber grating measurement anchor rod. Background Art

[0002] Traditional anchor measurement devices have the following disadvantages:

[0003] 1. Traditional pressure sensors measure anchor pressure at fewer measurement points, the measurement range is not comprehensive, and the measurement data has errors;

[0004] 2. Traditional pressure sensor measurement anchors cannot realize the connection of multiple measurement anchors in series, making it difficult to form a regional measurement network;

[0005] 3. The anchor measurement data measured by traditional pressure sensors cannot display the anchor pressure conditions in real time.

[0006] 4. Traditional pressure sensors measuring anchor rods are susceptible to corrosion after long-term operation and are not resistant to high temperatures. Utility Model Content

[0007] The utility model aims to provide a fiber grating measuring anchor rod to solve the problems raised in the above background technology.

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a fiber grating measuring anchor rod, including a column, an optical fiber, a grating sensor, a light protection cover, a connection box, a pressure monitor, and a demodulator. A spiral groove with a width of 3-5mm and a depth of about 2-4mm from top to bottom is arranged on the surface of the column. The optical fiber and the grating sensor are connected by laser welding. The optical fiber connected to the grating sensor is placed in the spiral groove on the column from top to bottom. The optical fiber fixing glue fixes the optical fiber on the threaded surface of the column to ensure that there is at least one grating sensor for each circle of thread. A horizontal groove is arranged on the bottom cross section of the column, and the optical fiber is arranged in the horizontal groove. A vertical hollow area with a width of about 3-5mm from top to bottom is arranged in the middle of the column. The optical fiber reaching the bottom passes through the area and returns to the upper end of the column. The optical fiber protective shell is fixed on the surface of the optical fiber. A connection box is arranged on the upper end of the column. The optical fiber is connected in parallel to the pressure monitor inside the box and the demodulator outside.

[0009] Preferably, the output end of the optical fiber is connected to the lower end of the pressure monitor, the pressure monitor identifies the signal transmitted from the grating sensor, and the pressure monitor is connected to the warning light outside the connection box. The pressure monitor uses a photodetector to convert the optical signal into an electrical signal, and uses single-chip microcomputer technology to process the electrical signal and set a fixed pressure threshold. When the lateral pressure on the anchor rod is lower than the set pressure threshold, the warning light is green, and when the pressure is greater than the fixed threshold, the warning light is red.

[0010] Preferably, the optical fiber at the bottom end of the column can be connected in series with the optical fibers at the bottom ends of other anchor rods to form a fiber grating measurement network.

[0011] Preferably, the optical fiber protective shell is made of resin material, which is resistant to high temperature and corrosion.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] 1. Fiber Bragg Grating Measuring Anchor The fiber is spirally wound around the anchor column and the cross section of the column, increasing the number of grating sensors on each cross section of the anchor, and can monitor the magnitude and location of the force on the anchor;

[0014] 2. The fiber grating measuring anchor bottom optical fiber can be connected in series with other anchor optical fibers to form a regional measurement network, increasing the measurement flexibility of the equipment;

[0015] 3. This fiber grating measurement anchor adopts a separate pressure monitor, through which real-time pressure alarm display can be realized.

[0016] 4. The protective shell of the fiber grating measuring anchor rod is made of resin material and has the characteristics of high temperature resistance and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the measuring anchor rod of the utility model;

[0018] Figure 2 It is a schematic diagram of the main structure of the utility model;

[0019] Figure 3 This is a schematic diagram of the control workflow of the utility model;

[0020] In the figure: 1. column, 2. optical fiber, 3. grating sensor, 4. optical fiber protective shell, 5. connection box, 6. pressure monitor, 7. warning light, 8. demodulator. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-3 , the utility model provides a technical solution:

[0023] In order to solve the problems of incomplete force and data errors, a fiber grating measurement anchor rod is proposed, including a column 1, an optical fiber 2, a grating sensor 3, an optical fiber protective shell 4, a connection box 5, a pressure monitor 6, and a demodulator 8. A spiral groove with a width of 3-5mm and a depth of about 2-4mm from top to bottom is arranged on the surface of the column 1. The optical fiber 2 and the grating sensor 3 are connected by laser welding. The optical fiber 2 connected to the grating sensor 3 is placed from top to bottom into the spiral groove on the column 1, and the optical fiber 2 is fixed to the thread surface of the column 1 with optical fiber fixing glue to ensure that there is at least one grating sensor 3 in each circle of thread. A horizontal groove is arranged on the bottom cross section of the column 1, and the optical fiber 2 is placed in the horizontal groove. A vertical hollow area with a width of 3-5mm from top to bottom is arranged in the middle of the column 1. The optical fiber 2 reaching the bottom passes through the area and returns to the upper end of the column 1. A connection box 5 is arranged on the upper end of the column 1, and the optical fiber 2 is connected in parallel to the pressure monitor 6 inside the box 5 and the demodulator 8 outside. Working principle: The optical fiber 2 is spirally wound into the spiral groove set in the anchor column 1. The optical fiber 2 passing through the upper part is connected to the pressure monitor 6 in the connection box 5 and the external demodulator 8. After the bottom of the anchor is inserted into the target and fixed, the pressure from the target will act on the anchor column 1 through the optical fiber protective shell 4. The grating sensor 3 wrapped around the column 1 is also subjected to the pressure from the target. After the grating sensor 3 is subjected to the pressure, it will send the optical signal to the pressure monitor 6 and the demodulator 8. The pressure monitor 6 will feed back the pressure situation to the warning light 7. The demodulator 8 will make a detailed processing and analysis of the signal, demodulate the signal, and obtain specific data and the strain situation of the anchor. This measuring anchor improves the monitoring of the strain capacity of the anchor and improves the accuracy and comprehensiveness of the data.

[0024] In order to realize the automatic display function of anchor rod pressure measurement, a fiber grating anchor rod measurement is proposed. The output end of the optical fiber 2 is connected to the lower end of the pressure monitor 6. The pressure monitor 6 identifies the signal from the grating sensor 3. The pressure monitor 6 is connected to the warning light 7 outside the connection box 5. The pressure monitor 6 converts the optical signal into an electrical signal using a photodetector. The single-chip microcomputer technology processes the electrical signal and sets a fixed pressure threshold. When the lateral pressure on the anchor rod is lower than the set pressure threshold, the warning light 7 is green. When the pressure is greater than the fixed threshold, the warning light 7 is red. The automatic display function of anchor rod measurement is realized.

[0025] In order to improve the measurement capability of the anchor rod area, a fiber grating measurement anchor rod is proposed. The optical fiber 2 at the bottom end of the column 1 can be connected in series with the optical fibers 2 at the bottom ends of other anchor rods to form a fiber grating measurement network.

[0026] In order to improve the adaptability of the equipment to the working environment, a fiber grating measurement anchor rod is proposed. The fiber protective shell 4 uses a resin material with high temperature resistance and corrosion resistance, which can better provide high temperature resistance and corrosion resistance for the equipment.

[0027] The working principle of the utility model is as follows: the optical fiber 2 is spirally installed in the spiral groove set in the anchor column 1, and the optical fiber 2 passing through the upper part is connected to the pressure monitor 6 in the connection box 5 and the external demodulator 8. After the bottom of the anchor is inserted into the target and fixedly supported, the axial pressure or tensile force from the target will act on the anchor column 1, and the grating sensor 3 wrapped on the column 1 is subjected to the pressure or tensile force transmitted by the target, and the spacing of the grating sensor 3 changes. The change in the grating spacing will cause the wavelength of the optical signal to change. The optical fiber will send the changed optical signal to the pressure monitor 6 and the demodulator 8. The pressure monitor 6 will feed back the pressure situation to the warning light 7. When the lateral pressure on the anchor is lower than the set pressure threshold, the warning light 7 is green. When the pressure is greater than the fixed threshold, the warning light 7 is red. The demodulator 8 will make a detailed processing and analysis of the signal, demodulate the signal, and obtain specific data and the strain of the anchor.

[0028] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fiber grating measuring anchor rod, comprising a column (1), an optical fiber (2), a grating sensor (3), an optical fiber protective shell (4), a connection box (5), a pressure monitor (6), and a demodulator (8), characterized in that: The surface of the column (1) is provided with a spiral groove from top to bottom. The optical fiber (2) and the grating sensor (3) are welded by laser. The optical fiber (2) connected to the grating sensor (3) is placed in the spiral groove on the column (1) from top to bottom. The optical fiber fixing glue fixes the optical fiber (2) on the thread surface of the column (1). Each circle of the thread has at least four grating sensors (3), and each grating sensor (3) is spaced at the same distance from each other. The bottom cross section of the column (1) is provided with a horizontal groove. The optical fiber (2) is arranged in the horizontal groove. A vertical hollow area is provided from top to bottom at the center of the spiral column (1). The optical fiber (2) reaching the bottom passes through the area and returns to the upper end of the column (1). The optical fiber protective shell (4) is fixed on the surface of the optical fiber (2). A connection box (5) is provided at the upper end of the column (1). The optical fiber (2) is connected in parallel to a pressure monitor (6) inside the connection box (5) and a demodulator (8) outside the connection box.

2. The fiber Bragg grating measuring anchor rod according to claim 1, characterized in that: The output end of the optical fiber (2) is connected to the lower end of the pressure monitor (6). The pressure monitor (6) identifies the optical signal transmitted from the grating sensor (3). The pressure monitor (6) is connected to the warning light (7) outside the connection box (5). The pressure monitor (6) converts the optical signal into an electrical signal using a photodetector.

3. The fiber Bragg grating measuring anchor rod according to claim 1, characterized in that: The optical fiber (2) is connected in series with the optical fibers (2) at the bottom ends of other anchor rods at the bottom end of the column (1) to form a fiber grating measurement network.

4. The fiber Bragg grating measuring anchor rod according to claim 1, characterized in that: The optical fiber protective shell (4) is made of resin material.

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