CN112161582A - Combined range-adjustable optical fiber multipoint delayer and measuring method - Google Patents
Combined range-adjustable optical fiber multipoint delayer and measuring method Download PDFInfo
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- CN112161582A CN112161582A CN202010754481.0A CN202010754481A CN112161582A CN 112161582 A CN112161582 A CN 112161582A CN 202010754481 A CN202010754481 A CN 202010754481A CN 112161582 A CN112161582 A CN 112161582A
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 11
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 61
- 239000010959 steel Substances 0.000 claims abstract description 61
- 238000000926 separation method Methods 0.000 claims abstract description 26
- 241000935974 Paralichthys dentatus Species 0.000 claims abstract description 25
- 239000000758 substrate Substances 0.000 claims abstract description 25
- 239000000835 fiber Substances 0.000 claims description 39
- 230000032798 delamination Effects 0.000 claims description 25
- 238000007789 sealing Methods 0.000 claims description 21
- 238000009434 installation Methods 0.000 claims description 16
- 239000003245 coal Substances 0.000 claims description 12
- 230000001681 protective effect Effects 0.000 claims description 12
- 238000006073 displacement reaction Methods 0.000 claims description 11
- 230000003287 optical effect Effects 0.000 claims description 8
- 210000000078 claw Anatomy 0.000 claims description 6
- 230000000149 penetrating effect Effects 0.000 claims description 6
- 238000000691 measurement method Methods 0.000 claims description 5
- 238000005520 cutting process Methods 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 3
- 238000004080 punching Methods 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 abstract description 15
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 238000005259 measurement Methods 0.000 description 6
- 239000011435 rock Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000000306 component Substances 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000005483 Hooke's law Effects 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
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- 238000004519 manufacturing process Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/18—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
- E21F17/02—Suspension devices for tubes or the like, e.g. for ventilating ducts
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
- E21F17/18—Special adaptations of signalling or alarm devices
- E21F17/185—Rock-pressure control devices with or without alarm devices; Alarm devices in case of roof subsidence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
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Abstract
The invention discloses a combined range-adjustable optical fiber multipoint delayer and a measuring method, belonging to the technical field of mine safety monitoring, wherein the structure of the delayer comprises a delayer sensor, a mounting part and an adjusting part, the delayer sensor comprises a substrate, a steel wire rope perforation is arranged in the center of the substrate, a cantilever beam is arranged around the steel wire rope perforation, and an optical fiber grating is arranged on the cantilever beam; the base plate is also provided with an inner core, a guide rod is movably arranged in a through hole on the inner core, the guide rod penetrates through the through hole and then abuts against a stress point of the cantilever beam, and a steel wire rope is fixed at the other end of the guide rod; one end of the mounting piece is mounted on the base plate, the other end of the mounting piece is provided with a sleeve, and the steel wire rope extends out of the sleeve; the regulating part comprises a spring, one end of the spring is connected with a spring fixing hook, the other end of the spring is connected to the steel wire rope through a stretching piston, and the spring fixing hook is connected with an anchor fluke. The technical scheme of the invention can realize three-point and more than three-point separation monitoring and provides a technical means for monitoring the safety state of the complex top plate.
Description
Technical Field
The invention relates to the technical field of mine safety monitoring, in particular to an optical fiber delamination apparatus, and specifically relates to a combined range-adjustable optical fiber multipoint delamination apparatus and a measurement method.
Background
The coal mine roof belongs to a typical layered structure, when underground coal seams are mined, rock mass balance around a working face is damaged, along with the continuous propulsion of the working face, the roof loses support and sinks to different degrees, and the sinking amount determines the safety degree of the roof; the displacement monitoring of the old roof and the immediate roof of the roof is a necessary technical means for judging the safety of the roof. When meeting complicated roofs such as coal mine roof is thick, the roof is fragile or the rock mass is softer, the requirement of roadway safety monitoring can not be met only by two monitoring points, and the multipoint absciss layer sensor is needed to carefully observe the safety condition of the roof.
Currently, an electronic sensing device is mostly adopted for top plate safety monitoring, and inaccurate measurement is easily caused due to electromagnetic interference on a working surface; the existing fiber grating separation layer sensor adopts optical signals as a measuring and transmitting medium, is anti-electromagnetic interference, high in precision and safe in nature, but is limited by complex structures such as precise guide rails, gears and the like, only can be used for manufacturing the fiber grating separation layer sensor for monitoring two points, and the fiber multi-point separation layer sensor with more than three points cannot be manufactured.
Disclosure of Invention
In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a combined range-adjustable optical fiber multi-point delamination apparatus and a measurement method thereof, so as to realize three-point and more than three-point delamination monitoring and provide a technical means for monitoring the safety state of a complex roof.
The technical scheme adopted by the invention for solving the technical problems is as follows:
in one aspect, the present invention provides a combined range-adjustable optical fiber multi-point delamination apparatus, comprising:
the separation layer instrument sensor comprises a substrate, wherein at least three cantilever beam fixing positions are arranged on the substrate, the cantilever beam fixing positions are distributed on the same circumference around the center of the substrate, and a plurality of steel wire rope through holes are formed in the center of the substrate; the cantilever beam fixing position is fixedly provided with a cantilever beam, the upper side of the cantilever beam is provided with a first fiber grating, and the lower side of the cantilever beam is provided with a second fiber grating; an inner core is fixedly arranged on the base plate, a plurality of through holes are formed in the inner core, and the through holes are concentric with the end face of the cantilever beam; a guide rod is movably arranged in the through hole, one end of the guide rod penetrates through the through hole and then abuts against a stress point of the cantilever beam, and one or more threaded holes are formed in the other end of the guide rod; a steel wire rope is fixed in the threaded hole and extends to the other side of the base plate after penetrating through the cantilever beam and the base plate;
one end of the mounting piece is mounted on the base plate, the other end of the mounting piece is provided with a sleeve, the outer side wall of the sleeve is provided with a claw hook, and the steel wire rope penetrates through the sleeve and extends out of the tail end of the sleeve;
the adjusting piece comprises a spring, one end of the spring is connected with the spring fixing hook, and the other end of the spring is connected with the extension piston; the other side of the stretching piston is connected to the steel wire rope, and the other side of the spring fixing hook is connected with an anchor claw.
Furthermore, a protective shell is arranged on a substrate of the separation layer instrument sensor, the protective shell comprises a cylinder and a rear cylinder, one end of the cylinder is connected with the substrate, the other end of the cylinder is provided with a rear cover, the rear cylinder is arranged on the rear cover and communicated with the cylinder, and the diameter of the rear cylinder is smaller than that of the cylinder; the cantilever beam, the inner core and the guide rod are covered by the protective shell.
Furthermore, the spring and the extension piston are both located in the spring sleeve, the extension piston can move along the spring sleeve, and the spring fixing hook is fixedly installed at one end of the spring sleeve.
Furthermore, a sealing waterproof structure is arranged at the perforated position of the steel wire rope.
Furthermore, the rear cover is provided with a sealing ring mounting groove and an optical cable waterproof joint for fixing an optical cable.
Furthermore, the matching position of the rear cylinder and the rear cover is connected through threads, and a sealing ring is arranged at the connecting position.
Furthermore, the components of the separation instrument sensor, the mounting piece and the adjusting piece are all subjected to waterproof sealing treatment.
On the other hand, the invention also provides a measuring method of the combined range-adjustable optical fiber multi-point delamination apparatus, which comprises the following steps:
mounting the combined range-adjustable optical fiber multi-point separation instrument on a structure to be measured;
after the measured structure deforms, pulling the fluke to enable the stretching piston to pull the spring to stretch, wherein the stretching amount of the spring is the displacement required to be measured by the delaminating instrument sensor;
the elastic force generated by the extension of the spring is transmitted to the cantilever beam through the steel wire rope and the guide rod;
the flexural strain of the cantilever is represented by the wavelength change of the first grating fiber and the second grating fiber;
acquiring the deformation of the measured structure according to the flexural strain of the cantilever;
the calibration formula of the displacement x, the flexural strain and the fiber grating wavelength variation is as follows:
in the above formula:
Min order to be able to measure the amount of strain in deflection,
λBis the center wavelength of the fiber grating,
k is the coefficient of elasticity of the polymer,
e is the modulus of elasticity of the cantilever beam,
h is the thickness of the cantilever beam,
l is the length of the cantilever beam,
b is the width of the cantilever beam,
ΔλB1is the variation of the center wavelength of the first fiber grating,
ΔλB2is the variation of the center wavelength of the second fiber grating.
Further, the installation of combined range-adjustable optical fiber multipoint delayer on the structure to be measured includes:
s1: punching mounting holes matched with mounting pieces and adjusting pieces of the combined range-adjustable optical fiber multipoint separation instrument on a coal mine roof;
s2: penetrating a steel wire rope and a spring sleeve of an adjusting piece into a hollow mounting rod to expose an anchor fluke at the top end of the mounting rod, inserting the mounting rod into a mounting hole, and jacking the anchor fluke into an old jacking position of a coal mine roof;
s3: the mounting rod is pulled out, the steel wire rope is slightly pulled, and the anchor fluke is ensured to be clamped in the mounting hole;
s4: repeating S2 and S3, and placing N groups of combined bodies of the adjusting pieces and the steel wire ropes into the mounting holes, wherein N is a natural number larger than 1;
s5: inserting the steel wire ropes in the previous step into a sleeve of the mounting piece, and inserting the mounting piece into the mounting hole for fixing;
s6: sequentially penetrating the steel wire rope through hole on the base plate and the threaded hole on the guide rod;
s7: fixedly connecting the substrate with the mounting piece;
s8: sequentially stretching the steel wire ropes and the springs of the adjusting parts according to the installation sequence, so that all the steel wire ropes are fixedly connected with the corresponding guide rods;
s9: and cutting off the redundant part of the steel wire rope, and installing a protective shell of the separation instrument sensor to complete the installation of the combined range-adjustable optical fiber multipoint separation instrument.
Compared with the prior art, the invention has the beneficial effects that:
1. the combined range-adjustable optical fiber multipoint delayer does not need complex structures such as a precise guide rail and a gear, is simple in structure and resistant to impact, adopts the fiber grating sensing principle, is used for monitoring and transmitting optical signals, does not need power supply, is intrinsically safe, eliminates potential safety hazards when applied in flammable and explosive environments, and is very suitable for roof safety monitoring in complex and severe environments under coal mines.
2. The combined range-adjustable optical fiber multipoint delayer does not need a measuring circuit, has a simpler structure, is convenient to install, saves cost, has high reliability, does not consume electric energy, and can carry out continuous measurement.
3. According to the combined type range-adjustable optical fiber multipoint delaminating instrument disclosed by the invention, on the premise that the parameters of a sensor of the delaminating instrument are not changed, the difference of the number of measurement points can be realized only by increasing or decreasing the number of the cantilever beams, the variation of the sensor range can be realized by adjusting the length, the line diameter and the number of turns of the spring sleeve and the spring, the delaminating instrument has more than three-point delaminating monitoring capability, is suitable for monitoring the internal delaminating condition of a complex top plate, and provides detailed data for top plate treatment.
4. According to the combined type range-adjustable optical fiber multipoint delaminating instrument disclosed by the invention, when different application requirements appear, the sensor part of the delaminating instrument does not need to be changed, and only the external adjusting part needs to be changed, so that the batch production of the delaminating instrument sensor is facilitated, and the inventory pressure is reduced.
5. The combined range-adjustable optical fiber multipoint delayer is provided with the protective shell, the mounting piece, the spring sleeve and the like, so that core components are comprehensively and effectively protected, and the use reliability and the service life are ensured; the moving amount of the steel wire rope in the sensor part of the separation instrument is smaller than 1mm, and a sealing waterproof structure is arranged in the steel wire rope perforation of the base plate, so that the structural design of the separation instrument is superior to that of other optical fiber separation sensors in the prior art, and the corrosion of roof water to the sensor is prevented.
6. According to the combined type range-adjustable optical fiber multipoint delayer, a combined structure is formed among a delayer sensor, an installation part and an adjusting part, the sealing performance of a sensing part is good, and the delayer can be repeatedly used; when the sensor needs to be recycled, the sensor only needs to be separated from the mounting part, and the steel wire rope is cut off, so that the investment cost of a user is reduced.
7. According to the measuring method disclosed by the invention, the wavelength change of the fiber bragg grating and the flexural strain are in a linear one-to-one corresponding relation, when the parameters of the cantilever beam and the spring are determined values, the wavelength change of the fiber bragg grating and the elongation of the spring are in a linear one-to-one corresponding relation, the deformation of the measured structure is obtained through calculation, the data has scientific basis, and the accuracy is high.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram of an overall structure of a combined range-adjustable optical fiber multi-point delamination apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a substrate of the combined range-adjustable optical fiber multi-point delamination apparatus according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of an inner core of the combined range-adjustable optical fiber multi-point delamination apparatus according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a guide rod in the combined range-adjustable optical fiber multi-point delamination apparatus according to an embodiment of the present invention;
fig. 5 is a schematic diagram of the installation of the combined range-adjustable optical fiber multi-point delamination apparatus in the measurement method according to the embodiment of the invention.
In the figure: the device comprises a base plate 1, a cylinder 2, an inner core 3, a guide rod 4, a rear cylinder 5, a rear cover 6, a cantilever beam 7, a mounting part 8, a steel wire rope 9, a first steel wire rope 91, a second steel wire rope 92, a third steel wire rope 93, a spring sleeve 10, an extension piston 11, a spring fixing hook 12, a spring 13, a fluke 14, a first fluke 141, a second fluke 142, a third fluke 143, a sleeve 15, a delaminating instrument sensor 16, a tail cable 17, a mounting hole 18, an old roof 19 and a direct roof 20.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.
The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.
As shown in fig. 1, an embodiment of the present invention provides a combined range-adjustable optical fiber multi-point delamination apparatus, including:
the separation layer instrument sensor comprises a substrate 1, the structure of the substrate 1 is shown in figure 2, at least three cantilever beam fixing positions are arranged on the substrate 1, the cantilever beam fixing positions are distributed on the same circumference around the center of the substrate 1, and a plurality of steel wire rope through holes are formed in the center of the substrate 1; a cantilever beam 7 is fixedly installed at the cantilever beam fixing position, a first fiber grating is arranged on the upper side of the cantilever beam 7, and a second fiber grating is arranged on the lower side of the cantilever beam 7; an inner core 3 is fixedly arranged on the base plate 1, the structure of the inner core 3 is shown in fig. 3, a plurality of through holes are formed in the inner core 3, and the through holes are concentric with the end face of the cantilever beam 7; a guide rod 4 is movably arranged in the through hole, the structure of the guide rod 4 is shown in figure 4, one end of the guide rod 4 penetrates through the through hole and then abuts against the stress point of the cantilever beam 7, and one or more threaded holes are formed in the other end of the guide rod 4; specifically, the guide rod 4 of the embodiment is provided with two threaded holes, a steel wire rope 9 is fixed in the threaded holes, and the steel wire rope 9 passes through the cantilever beam 7 and the base plate 1 and then extends to the other side of the base plate 1;
one end of the mounting part 8 is mounted on the base plate 1, the other end of the mounting part 8 is provided with a sleeve 15, the outer side wall of the sleeve 15 is provided with a claw hook, and the steel wire rope 9 penetrates through the sleeve 15 and extends out of the tail end of the sleeve 15;
the adjusting piece comprises a spring 13, one end of the spring 13 is connected with the spring fixing hook 12, and the other end of the spring 13 is connected with the extension piston 11; the other side of the extension piston 11 is connected to the steel wire rope 9, and the other side of the spring fixing hook 12 is connected with a fluke 14.
The claw hook and fluke 14 are both curved claw-like structures.
In order to protect important components, a protective shell is arranged on a substrate 1 of the separation instrument sensor and comprises a cylinder 2 and a rear cylinder 5, one end of the cylinder 2 is connected with the substrate 1, the other end of the cylinder 2 is provided with a rear cover 6, the rear cylinder 5 is arranged on the rear cover 6 and communicated with the cylinder 2, and the diameter of the rear cylinder 5 is smaller than that of the cylinder 2; the protective casing covers the cantilever beam 7, the inner core 3 and the guide rod 4.
The spring 13 and the extension piston 11 are both located in the spring sleeve 10, the extension piston 11 can move along the spring sleeve 10, and the spring fixing hook 12 is fixedly installed at one end of the spring sleeve 10.
In order to prevent the corrosion of the sensor caused by the water of the top plate, a sealing waterproof structure is arranged at the perforated part of the steel wire rope. Specifically, the sealing waterproof structure can adopt sealing grease or a rubber ring.
And a sealing ring mounting groove and an optical cable waterproof joint for fixing an optical cable are arranged on the rear cover 6. And a sealing ring, specifically an O-shaped ring and the like, is arranged in the sealing ring mounting groove, so that the waterproof sealing of the sensing part is realized.
The matching part of the rear cylinder 5 and the rear cover 6 is connected through threads, and a sealing ring is arranged at the connecting part and adopts an O-shaped ring.
The constituent parts (spring 13, etc.) of the delamination instrument sensor, the mounting member 8, and the adjustment member are all subjected to waterproof sealing treatment. The waterproof sealing treatment is a prior art well known to those skilled in the art, and the detailed sealing treatment process is not described herein.
The parameters of the sensing part of the combined range-adjustable optical fiber multi-point separation instrument are unchanged, and the number of the cantilever beams 7 is increased or decreased only according to the difference of the number of the measuring points; the adjusting part is arranged, and the measuring range of the sensor can be changed by adjusting the lengths, the wire diameters and the turns of the spring sleeve 10 and the spring 13.
On the other hand, the embodiment further provides a measurement method of the combined range-adjustable optical fiber multi-point delamination apparatus, including:
mounting the combined range-adjustable optical fiber multi-point separation instrument on a structure to be measured;
after the measured structure deforms, pulling the fluke to enable the stretching piston to pull the spring to stretch, wherein the stretching amount of the spring is the displacement required to be measured by the delaminating instrument sensor;
the elastic force generated by the extension of the spring is transmitted to the cantilever beam through the steel wire rope and the guide rod;
the flexural strain of the cantilever is represented by the wavelength change of the first grating fiber and the second grating fiber;
acquiring the deformation of the measured structure according to the flexural strain of the cantilever;
the calibration formula of the displacement x, the flexural strain and the fiber grating wavelength variation is as follows:
in the above formula:
Min order to be able to measure the amount of strain in deflection,
λBis the center wavelength of the fiber grating,
k is the coefficient of elasticity of the polymer,
e is the modulus of elasticity of the cantilever beam,
h is the thickness of the cantilever beam,
l is the length of the cantilever beam,
b is the width of the cantilever beam,
ΔλB1is the variation of the center wavelength of the first fiber grating,
ΔλB2is the variation of the center wavelength of the second fiber grating.
As shown in fig. 5, the installation of the combined span-adjustable optical fiber multi-point delamination apparatus on a structure to be tested includes:
s1: and punching a mounting hole 18 matched with the mounting piece and the adjusting piece of the combined range-adjustable optical fiber multipoint delaminating instrument on a coal mine roof.
S2: the steel wire rope and the spring sleeve 10 of the adjusting piece penetrate into the hollow mounting rod, the anchor fluke 14 is exposed at the top end of the mounting rod, the mounting rod is inserted into the mounting hole 18, and the anchor fluke 14 is jacked into the old roof 19 of the coal mine roof.
Specifically, the old roof 19 and the immediate roof 20 are coal mining terms, and the old roof 19 is a basic roof and is positioned above the immediate roof 20 or the false roof, and is a thick and hard rock stratum which is not easy to fall. After the extraction is finished, the direct roof collapses for a period of time, a whole block of roof rock, namely a basic roof, commonly called an old roof, is collapsed, the first time of collapse of the working face is formed, and the second time of collapse is once every other distance, so that a period of pressure is formed. The direct roof 20 is located above a false roof or a coal seam (when no false roof exists), generally consists of one or more layers of shale, siltstone and other rock strata which are easy to collapse, and the rock strata collapse after being pulled back.
In S2, the size of fluke 14 is larger than the inner diameter of the installation rod, the spring tube and the first wire rope 91 of the first fluke 141 are inserted into the hollow installation rod, the first fluke 141 is exposed at the top end of the installation rod, the installation rod is inserted into the installation hole 18, the first fluke 141 is forced to be pushed into the old top 19 position on the top plate, and the depth of the position can be determined according to the insertion length of the installation rod.
S3: the mounting rod is withdrawn and first cable 91 is pulled slightly to ensure that first fluke 141 is captured in mounting hole 18.
S4: and repeating S2 and S3, and placing N groups of combined bodies of the adjusting pieces and the steel wire ropes into the mounting holes, wherein N is a natural number larger than 1. Specifically, a second fluke 142-spring sleeve 10-second steel wire rope 92 assembly and a third fluke 143-spring sleeve 10-third steel wire rope 93 assembly are sequentially placed into a preset position of the mounting hole 18.
S5: the plurality of steel cables 9 in the previous step are inserted into the sleeve 15 of the mounting member 8, and the mounting member 8 is inserted into the mounting hole 18 and fixed.
S6: the rear cylinder 5 of the sensor is unscrewed, and the steel wire rope 9 sequentially passes through the steel wire rope through hole on the base plate 1 and the threaded hole on the guide rod 4.
S7: the substrate 1 and the mounting member 8 are fastened and connected by screws.
S8: and sequentially stretching the steel wire ropes and the springs of the adjusting parts according to the mounting sequence, so that all the steel wire ropes are fixedly connected with the corresponding guide rods. Specifically, the first steel wire rope 91-spring structure is stretched, so that the first steel wire rope 91 generates prestress, and the first steel wire rope 91 is fixed with the guide rod 4 through two threaded holes in the guide rod 4; and then sequentially stretching a second wire rope 92-spring structure, a third wire rope 93-spring structure and a wire rope N-spring structure, so that all the wire ropes 9 are fixed with the corresponding guide rods 4, and the wire ropes 9 are fixed in threaded holes of the guide rods 4 through screws.
S9: and cutting off the redundant part of the steel wire rope, screwing the rear barrel 5 so as to install the protective shell of the separation instrument sensor 16, and completing the installation of the combined type range-adjustable optical fiber multipoint separation instrument.
And the rear cover 6 is provided with a waterproof optical cable joint for connecting a tail cable 17.
In order to ensure the accuracy of the measured data of the sensor, the sensor can be calibrated after the sensor is packaged, the calibration equipment is an electronic displacement calibration platform, and the electronic displacement calibration platform is a product in the prior art, such as an HLC series precise linear displacement sensor.
The specific calibration process comprises the following steps:
the calibration interval is set to be 10mm (or other interval lengths) by fixing the separation instrument sensor 16 and the steel wire rope 9, the maximum measurement range value is calibrated from 0mm in the positive stroke in sequence, then the negative stroke calibration is carried out, the maximum measurement range value is calibrated to 0mm in sequence, and the steps are repeated for 3 times. And recording the wavelengths of the first fiber bragg grating and the second fiber bragg grating and the actual displacement of the calibration platform in the calibration process, and then calculating each parameter value.
In this embodiment, the flexural strain of the cantilever beam 7 is represented by the wavelength change of the first grating fiber and the second grating fiber, and the deformation of the structure to be measured is obtained according to the flexural strain of the cantilever beam 7, and the specific principle and the operation method thereof are as follows:
strain of constant strength cantilever beamMThe relationship to the load F is:
wherein: e is the elastic modulus of the cantilever beam; h is the thickness of the cantilever beam; l is the length of the cantilever beam; b is the width of the cantilever beam;
the load F is generated by spring tension, according to hooke's law:
F＝-kx (2)
wherein: k is the elastic coefficient of the spring; x is the deformation amount of the spring;
the following can be seen from formulas (1) and (2):
the prior art and the data show that the wavelength change Δ λ is generated by temperature and strainB＝0.74λB BWherein λ isBThe FBG center wavelength (known quantity),Bis strain. Namely:
after the deformation is generated, the strain of the two gratings is as follows:
B1＝T+M (5)
B2＝T-M (6)
whereinTIn order to influence the strain caused by the temperature,Mstrain due to deflection.
From formulae (5) and (6):
is shown by the formula (4)
Fiber Bragg Grating (FBG) wavelength variation
And flexural strainMLinear and one-to-one correspondence.
Meanwhile, the temperature has the same strain on the grating under the same environment, namelyTBy combining formula (1), formula (2) and formula (3) eliminatesTThereby eliminating temperature from the measurement resultsMThe influence of (c).
From formulae (3) and (8):
when the cantilever beam parameter and the spring parameter are determined values, the wavelength of the Fiber Bragg Grating (FBG) changes
Linear and one-to-one correspondence with spring elongation.
When the measuring range of the sensor needs to be changed, the spring parameter k is changed.
When the cross section of the cantilever beam is circular, the thickness and the width of the cantilever beam are the diameter of the cantilever beam.
The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.
Other technical features than those described in the specification are known to those skilled in the art, and are not described herein in detail in order to highlight the innovative features of the present invention.
Claims (9)
1. The utility model provides an optic fibre multiple spot absciss layer appearance with adjustable combined range which characterized in that includes:
the separation layer instrument sensor comprises a substrate, wherein at least three cantilever beam fixing positions are arranged on the substrate, the cantilever beam fixing positions are distributed on the same circumference around the center of the substrate, and a plurality of steel wire rope through holes are formed in the center of the substrate; the cantilever beam fixing position is fixedly provided with a cantilever beam, the upper side of the cantilever beam is provided with a first fiber grating, and the lower side of the cantilever beam is provided with a second fiber grating; an inner core is fixedly arranged on the base plate, a plurality of through holes are formed in the inner core, and the through holes are concentric with the end face of the cantilever beam; a guide rod is movably arranged in the through hole, one end of the guide rod penetrates through the through hole and then abuts against a stress point of the cantilever beam, and one or more threaded holes are formed in the other end of the guide rod; a steel wire rope is fixed in the threaded hole and extends to the other side of the base plate after penetrating through the cantilever beam and the base plate;
one end of the mounting piece is mounted on the base plate, the other end of the mounting piece is provided with a sleeve, the outer side wall of the sleeve is provided with a claw hook, and the steel wire rope penetrates through the sleeve and extends out of the tail end of the sleeve;
the adjusting piece comprises a spring, one end of the spring is connected with the spring fixing hook, and the other end of the spring is connected with the extension piston; the other side of the stretching piston is connected to the steel wire rope, and the other side of the spring fixing hook is connected with an anchor claw.
2. The combined range-adjustable optical fiber multipoint delamination instrument as claimed in claim 1, wherein a protective casing is disposed on a substrate of the delamination instrument sensor, the protective casing comprises a cylinder and a rear cylinder, one end of the cylinder is connected to the substrate, the other end of the cylinder is provided with a rear cover, the rear cylinder is mounted on the rear cover and is communicated with the cylinder, and the diameter of the rear cylinder is smaller than that of the cylinder; the cantilever beam, the inner core and the guide rod are covered by the protective shell.
3. The combined range-adjustable fiber multi-point delamination apparatus as recited in claim 1, wherein the spring and the extension piston are both disposed within a spring sleeve, the extension piston is movable along the spring sleeve, and the spring fixing hook is fixedly mounted at one end of the spring sleeve.
4. The combined range-adjustable optical fiber multi-point delamination apparatus as recited in claim 1, wherein a waterproof and sealing structure is disposed at the perforation of the steel cable.
5. The combined range-adjustable optical fiber multipoint delamination apparatus according to claim 2, wherein the rear cover is provided with a sealing ring installation groove and a cable waterproof joint for fixing the optical cable.
6. The combined range-adjustable optical fiber multi-point delamination apparatus as recited in claim 2 or 5, wherein the fitting portion of the rear cylinder and the rear cover is connected by a screw thread, and a sealing ring is disposed at the connection portion.
7. The combined span-adjustable fiber multi-point delamination apparatus of claim 1 wherein the delamination apparatus sensors, the mounting member and the adjusting member are all subjected to a waterproof sealing process.
8. A method of measuring the combined span adjustable fiber multi-point delamination apparatus as defined in any of claims 1-7, comprising:
mounting the combined range-adjustable optical fiber multi-point separation instrument on a structure to be measured;
after the measured structure deforms, pulling the fluke to enable the stretching piston to pull the spring to stretch, wherein the stretching amount of the spring is the displacement required to be measured by the delaminating instrument sensor;
the elastic force generated by the extension of the spring is transmitted to the cantilever beam through the steel wire rope and the guide rod;
the flexural strain of the cantilever is represented by the wavelength change of the first grating fiber and the second grating fiber;
acquiring the deformation of the measured structure according to the flexural strain of the cantilever;
the calibration formula of the displacement x, the flexural strain and the fiber grating wavelength variation is as follows:
in the above formula:
Min order to be able to measure the amount of strain in deflection,
λBis the center wavelength of the fiber grating,
k is the coefficient of elasticity of the polymer,
e is the modulus of elasticity of the cantilever beam,
h is the thickness of the cantilever beam,
l is the length of the cantilever beam,
b is the width of the cantilever beam,
ΔλB1is the variation of the center wavelength of the first fiber grating,
ΔλB2is the variation of the center wavelength of the second fiber grating.
9. The measurement method according to claim 8, wherein the mounting of the combined span adjustable fiber multi-point delamination apparatus on a structure under test comprises:
s1: punching mounting holes matched with mounting pieces and adjusting pieces of the combined range-adjustable optical fiber multipoint separation instrument on a coal mine roof;
s2: penetrating a steel wire rope and a spring sleeve of an adjusting piece into a hollow mounting rod to expose an anchor fluke at the top end of the mounting rod, inserting the mounting rod into a mounting hole, and jacking the anchor fluke into an old jacking position of a coal mine roof;
s3: the mounting rod is pulled out, the steel wire rope is slightly pulled, and the anchor fluke is ensured to be clamped in the mounting hole;
s4: repeating S2 and S3, and placing N groups of combined bodies of the adjusting pieces and the steel wire ropes into the mounting holes, wherein N is a natural number larger than 1;
s5: inserting the steel wire ropes in the previous step into a sleeve of the mounting piece, and inserting the mounting piece into the mounting hole for fixing;
s6: sequentially penetrating the steel wire rope through hole on the base plate and the threaded hole on the guide rod;
s7: fixedly connecting the substrate with the mounting piece;
s8: sequentially stretching the steel wire ropes and the springs of the adjusting parts according to the installation sequence, so that all the steel wire ropes are fixedly connected with the corresponding guide rods;
s9: and cutting off the redundant part of the steel wire rope, and installing a protective shell of the separation instrument sensor to complete the installation of the combined range-adjustable optical fiber multipoint separation instrument.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010754481.0A CN112161582A (en) | 2020-07-30 | 2020-07-30 | Combined range-adjustable optical fiber multipoint delayer and measuring method |
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| CN202010754481.0A CN112161582A (en) | 2020-07-30 | 2020-07-30 | Combined range-adjustable optical fiber multipoint delayer and measuring method |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113155069A (en) * | 2021-03-15 | 2021-07-23 | 中煤科工开采研究院有限公司 | Mine roof separation layer measuring device and measuring method thereof |
| CN113790960A (en) * | 2021-09-08 | 2021-12-14 | 大连理工大学 | Variable sensitivity fiber grating sensor for monitoring fracture failure process under static load effect and use method |
| NL2028119B1 (en) * | 2021-04-15 | 2022-03-11 | Univ Anhui Sci & Technology | Multi-point continuous measurement device for a deep displacement of a coal seam roof |
-
2020
- 2020-07-30 CN CN202010754481.0A patent/CN112161582A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113155069A (en) * | 2021-03-15 | 2021-07-23 | 中煤科工开采研究院有限公司 | Mine roof separation layer measuring device and measuring method thereof |
| CN113155069B (en) * | 2021-03-15 | 2022-10-11 | 中煤科工开采研究院有限公司 | Mine roof separation layer measuring device and measuring method thereof |
| NL2028119B1 (en) * | 2021-04-15 | 2022-03-11 | Univ Anhui Sci & Technology | Multi-point continuous measurement device for a deep displacement of a coal seam roof |
| CN113790960A (en) * | 2021-09-08 | 2021-12-14 | 大连理工大学 | Variable sensitivity fiber grating sensor for monitoring fracture failure process under static load effect and use method |
| CN113790960B (en) * | 2021-09-08 | 2022-05-27 | 大连理工大学 | Variable sensitivity fiber grating sensor for monitoring fracture failure process under static load effect and use method |
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