CN214151083U - Underground low-frequency geophone - Google Patents
Underground low-frequency geophone Download PDFInfo
- Publication number
- CN214151083U CN214151083U CN202120338097.2U CN202120338097U CN214151083U CN 214151083 U CN214151083 U CN 214151083U CN 202120338097 U CN202120338097 U CN 202120338097U CN 214151083 U CN214151083 U CN 214151083U
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- Prior art keywords
- cantilever beam
- erect
- roof beam
- cantilever
- fiber grating
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- 239000000835 fiber Substances 0.000 claims abstract description 32
- 239000010935 stainless steel Substances 0.000 claims description 4
- 229910001220 stainless steel Inorganic materials 0.000 claims description 4
- 229910000838 Al alloy Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 238000005259 measurement Methods 0.000 abstract 1
- 239000003292 glue Substances 0.000 description 6
- 239000013307 optical fiber Substances 0.000 description 6
- 230000001133 acceleration Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 238000004806 packaging method and process Methods 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
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Abstract
The utility model provides a low frequency geophone in pit, includes T type base, T type base divide into the crossbeam and erects the roof beam, erect the roof beam and be located horizontally crossbeam center department setting, be located and erect the roof beam both sides and be provided with cantilever beam one and cantilever beam two respectively, the cantilever beam of wherein one side and both sides of erecting the roof beam is on the coplanar, it is provided with fiber grating with the lateral surface of cantilever beam coplanar to erect the roof beam, erects the roof beam respectively with leave the space between the cantilever beam of both sides, be provided with fixed terminal point one and fixed terminal point two on the fiber grating of space department, cantilever beam one inboard is provided with quality piece two, and two inboards of cantilever beam are provided with quality piece one. The invention has the characteristics of wide measurement range and high sensitivity.
Description
Technical Field
The utility model relates to a seismic exploration device technical field, in particular to low frequency geophone in pit.
Background
The seismic wave is vibration propagated from a seismic source to four places, and is also propagation of mechanical motion, and refers to an elastic wave which is generated from the seismic source and radiated to the periphery. The seismic exploration technology applied to seismic wave detection is also one of the most effective methods for solving oil and gas resources. Compared with the traditional vibration sensor, the optical fiber vibration sensor has the advantages of strong electromagnetic interference resistance, high sensitivity, good electrical insulation, safety, reliability and the like. Among the optical fiber sensors, the FBG sensor is the most widely used optical fiber sensor, and has advantages such as stable signal and multiplexing capability in addition to the advantages of the optical fiber sensor. The principle of the acceleration optical fiber vibration sensor based on the Bragg grating is that when the sensor receives a vibration signal, a mass inertia block displaces; under the combined action of the damping block and the elastic body, the optical fiber generates axial strain, and the central wavelength of the fiber grating is changed along with the axial strain, so that the effect of measuring vibration is achieved. The FBG geophone includes an cantilever beam type and a diaphragm type, and the most common structure of the FBG geophone is the cantilever beam type, which has a simple structure and is easy to realize. However, how to expand the frequency band range and improve the sensitivity is a problem to be solved urgently in further development of the traditional cantilever beam type fiber bragg grating sensor.
Disclosure of Invention
The not high, the not enough shortcoming of stability of sensitivity to current FBG vibration sensor existence, the utility model aims to provide a low frequency geophone in pit has the characteristics that measuring range is wide, sensitivity is high.
In order to realize the purpose, the utility model discloses a technical scheme is:
the utility model provides a low frequency geophone in pit, includes T type base 1, T type base 1 divide into the crossbeam and erects the roof beam, erect the roof beam and be located the setting of horizontally crossbeam center department, be located and erect the roof beam both sides and be provided with cantilever beam one 2 and cantilever beam two 3 respectively, erect wherein one side of roof beam and the cantilever beam of both sides on the coplanar, erect the roof beam and be provided with fiber grating 4 with the lateral surface of cantilever beam coplanar, erect the roof beam respectively with leave the space between the cantilever beam of both sides, be provided with fixed endpoint one 5 and fixed endpoint two 6 on the fiber grating 4 of space department, 2 inboards of cantilever beam are provided with quality piece two 8, and two 3 inboards of cantilever beam are provided with quality piece one 7.
The outer side edge of the cantilever beam is flush with the outer side edge of the cross beam.
The whole thickness of T type base 1 is the aluminum alloy material or the stainless steel material of 10 mm.
The fixed end point of each fiber grating 4 is 5 mm.
The utility model has the advantages that:
1. the utility model discloses measure the fiber grating sensing, increased the measuring range and the sensitivity of original cantilever beam.
2. The two-point packaging of the fiber bragg grating is adopted, so that the packaging difficulty can be reduced, and the chirp phenomenon can be avoided on the basis.
3. And numerical analysis and simulation are performed by adopting ANSYS software, and the sensor is prepared after the optimal mechanism of the sensor is obtained, so that a reliable theoretical basis is provided for the preparation of the sensor.
4. The utility model discloses an integration processing structure need not the equipment, improves sensitivity, and the quality piece adds in a flexible way, can adjust the wave detector parameter through suitably adjusting the quality piece quality.
Drawings
Fig. 1 is a schematic structural diagram of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 1:
example 1:
the length, width and height of the cantilever beams at two ends of the structure are respectively 45mm, 5mm and 0.5mm, and the length and width of the cross beam of the T-shaped base 1 are respectively 5mm and 50 mm; the length and width of the vertical beam are 45mm and 5mm respectively; the T-shaped base 1 is made of stainless steel with the overall thickness of 10 mm. The fixed end point of each fiber grating 4 is 5mm, a 353ND glue hot air gun is adopted to solidify for one hour when the fiber gratings 4 are packaged, one end of each fiber grating is fixed, prestress is applied, the other end point of each fiber grating is solidified for one hour by the 353ND glue hot air gun, a detector is fixed on a vibration table, the port of each fiber grating 4 is connected to a 130 demodulator, the acceleration is fixed, and detection is carried out in different frequency bands. The frequency it is suitable to detect is determined from the wavelength shift.
Example 2:
the length, width and height of the cantilever beams (2 and 3) at the two ends are respectively 45mm, 5mm and 1mm, and the length and width of the cross beam of the T-shaped base 1 are respectively 5mm and 50 mm; the length and width of the vertical beam are 45mm and 5mm respectively; the T-shaped base 1 is made of stainless steel with the overall thickness of 10 mm. The fixed end point of each fiber grating 4 is 5mm, ultraviolet curing glue is adopted when the fiber gratings 4 are packaged, curing and packaging are carried out by irradiating an ultraviolet lamp for a certain time, one end of each fiber grating is fixed, prestress is applied again, then the fiber gratings are packaged by the ultraviolet curing glue, curing is carried out by irradiating the fiber gratings for a certain time by the ultraviolet lamp, a detector is fixed on a vibrating table, the port of each fiber grating 4 is connected to a 130 demodulator, the acceleration is fixed, and detection is carried out at different frequency sections. The frequency it is suitable to detect is determined from the wavelength shift.
Example 3:
the length, width and height of the cantilever beams (2 and 3) at the two ends are respectively 45mm, 5mm and 0.5mm, and the length and width of the cross beam of the T-shaped base 1 are respectively 5mm and 50 mm; the length and width of the vertical beam are 45mm and 5mm respectively; the T-shaped base 1 is made of aluminum alloy with the whole thickness of 10 mm. The fixed end point of each fiber grating 4 is 5mm, when the fiber grating is packaged, 502 glue is adopted to solidify at room temperature for a certain time, one end is fixed, prestress is applied, the 502 glue is used to solidify at room temperature for another end point for a certain time, the detector is fixed on a vibration table, the fiber port is connected to a 130 demodulator, the acceleration is fixed, and detection is carried out at different frequency bands. The frequency it is suitable to detect is determined from the wavelength shift.
The utility model discloses a theory of operation:
the detector is fixed on a vibration table, when a vibration signal is in a direction perpendicular to the detector, the mass blocks (7 and 8) can cause the free ends of the cantilever beams (2 and 3) to move up and down under the action of inertia force, the deformation of the cantilever beams (2 and 3) can drive the fiber bragg grating 4 to generate strain, the fiber bragg grating 4 can be elongated or restored to the original state, the central wavelength of the fiber bragg grating 4 can be changed accordingly, and therefore, the vibration signal of the external environment can be obtained as long as the change amount of the central wavelength of the fiber bragg grating 4 is measured. In addition, the fiber grating 4 is in a suspended state, and the suspended design makes the fiber grating not easy to generate chirp.
Claims (4)
1. The utility model provides a low frequency geophone in pit, its characterized in that, includes T type base (1), T type base (1) divide into the crossbeam and erects the roof beam, erect the roof beam and be located the setting of horizontally crossbeam center department, be located and erect the roof beam both sides and be provided with cantilever beam one (2) and cantilever beam two (3) respectively, erect wherein one side of roof beam and the cantilever beam of both sides on the coplanar, erect the roof beam and be provided with fiber grating (4) with the lateral surface of cantilever beam coplanar, erect the roof beam respectively with leave the space between the cantilever beam of both sides, be provided with fixed endpoint one (5) and fixed endpoint two (6) on fiber grating (4) of space department, cantilever beam one (2) inboard is provided with quality piece two (8), and cantilever beam two (3) inboard is provided with quality piece (7).
2. A downhole low frequency geophone according to claim 1, wherein said cantilever beam outer side edge is flush with said beam outer side edge.
3. A downhole low frequency geophone according to claim 1, wherein said T-base (1) is of aluminium alloy or stainless steel material having an overall thickness of 10 mm.
4. A downhole low frequency geophone according to claim 1, wherein the fixed end point of each fiber grating (4) is 5 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120338097.2U CN214151083U (en) | 2021-02-06 | 2021-02-06 | Underground low-frequency geophone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120338097.2U CN214151083U (en) | 2021-02-06 | 2021-02-06 | Underground low-frequency geophone |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214151083U true CN214151083U (en) | 2021-09-07 |
Family
ID=77553352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120338097.2U Expired - Fee Related CN214151083U (en) | 2021-02-06 | 2021-02-06 | Underground low-frequency geophone |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214151083U (en) |
-
2021
- 2021-02-06 CN CN202120338097.2U patent/CN214151083U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20210907 |