A kind of sensitization structure for chirped phase-shift grating multi-point distributed strain sensing

Abstract

The utility model discloses a kind of Sensitizing structure for chirp phase shift grating multipoint site distributed strain sensing, including packaging tube, the both ends of packaging tube are respectively provided with end seal, optical cable is provided in packaging tube, the both ends of optical cable respectively from two end seal stretch out;Optical cable is provided with fiber grating, the utility model is filled with structure glue by first installing inner end cap and injecting structure glue, then inserting outer end cap, space of filling structure glue is formed between outer end cap and inner end cap, with outer end cap insertion, space becomes small, structure glue is extruded, excess part enters the gap between through hole one and optical cable and between outer end cap outer wall and packaging tube along the thread groove on through hole one, realizes the effective sealing of packaging tube end portion after solidification.It improves the sealing performance of packaging tube end portion, effectively prevent outside impurity, moisture etc. into packaging tube, protect the internal optical cable and fiber grating.

Description

Technical Field

[0001] This utility model relates to a sensitivity enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings, belonging to the field of vehicle control technology. Background Technology

[0002] In applications involving multi-point distributed strain sensing using chirped phase-shift gratings, the stability and reliability of the sensing structure are crucial. However, existing sensing structures have several shortcomings in terms of encapsulation, sealing, and installation protection. Firstly, many traditional structures employ a single sealing method, which is insufficient to effectively prevent external impurities and moisture from entering the encapsulation tube. Once these substances intrude, they can easily damage core components such as internal optical cables and fiber optic gratings, causing the sensing structure to malfunction and operate unreliably in complex environments. This significantly shortens the lifespan of the sensing structure and increases operating costs and maintenance complexity. Therefore, a sensitivity-enhancing structure for multi-point distributed strain sensing using chirped phase-shift gratings is proposed. Utility Model Content

[0003] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings, effectively preventing external impurities and moisture from entering the encapsulation tube, protecting the internal optical cables and fiber optic gratings, and ensuring that the sensing structure can operate stably and reliably in complex environments.

[0004] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: This utility model provides a sensitivity enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings, comprising:

[0005] The encapsulation tube is a hollow structure with openings at both ends;

[0006] There are two end seals, one at each end of the encapsulation tube, used to encapsulate the tube.

[0007] The optical cable is housed inside an encapsulation tube, with both ends of the cable extending from two end seals.

[0008] Fiber Bragg gratings are installed on optical cables and encapsulated in encapsulation tubes.

[0009] Preferably, the inner walls at both ends of the encapsulation tube are provided with inner ring shoulders, and the end seal includes:

[0010] The outer end cap is inserted into the end of the encapsulation tube;

[0011] The inner end cap is installed inside the encapsulation tube and rests against the inner ring shoulder.

[0012] When the outer end cap and the inner end cap are installed at the ends of the encapsulation tube, there is a space between the outer end cap and the inner end cap for filling with structural adhesive.

[0013] Preferably, the outer end cap and the inner end cap are respectively provided with a through hole one and a through hole two for the optical cable to pass through.

[0014] Preferably, both the through hole and the outer wall of the outer end cap are provided with threaded grooves.

[0015] Preferably, a sealing ring is provided inside the second through hole for sealing the gap between the second through hole and the optical cable.

[0016] Preferably, the outer wall of the sealing ring is conical, and the shape of the second through hole is adapted to the shape of the sealing ring;

[0017] The outer end cap has a pressure plate connected to its side wall via a connecting rod.

[0018] When the outer end cap is installed at the end of the encapsulation tube, the pressure plate presses against the large end of the sealing ring.

[0019] Preferably, multiple ear plates are distributed circumferentially on the sidewalls of the two outer end caps, and a movable plate is provided on the side of any outer end cap away from the encapsulation tube. Multiple connecting rods are distributed on the movable plate, and one end of each connecting rod passes through the ear plate on the outer end cap on the same side and is fixed to the corresponding ear plate on the other outer end cap.

[0020] Preferably, a groove is provided on the outer end cap near the movable plate to define the position of the bolt thread end.

[0021] Preferably, the encapsulation tube is made of transparent glass.

[0022] Preferably, an optocoupler is connected to the optical cable.

[0023] Compared with existing technologies:

[0024] 1. This utility model involves first installing the inner end cap and injecting structural adhesive, then inserting the outer end cap. A space filled with structural adhesive is formed between the inner and outer end caps. As the outer end cap is inserted, the space decreases, compressing the structural adhesive. Excess adhesive flows along the threaded groove on through-hole one into the gap between through-hole one and the optical cable, as well as between the outer wall of the outer end cap and the encapsulation tube. After solidification, it effectively seals the end of the encapsulation tube. Simultaneously, during the installation of the outer end cap, a pressure plate presses down on the sealing ring, forcing it into through-hole two, sealing the gap between through-hole two and the optical cable, preventing structural adhesive from flowing into the encapsulation tube. This dual-sealing design improves the sealing performance of the encapsulation tube end, effectively preventing external impurities and moisture from entering the encapsulation tube, protecting the internal optical cable and fiber optic grating, ensuring stable and reliable operation of the sensing structure in complex environments, and extending the service life of the sensing structure.

[0025] 2. This utility model simplifies the installation process and improves efficiency by allowing the two outer end caps to be installed simultaneously through rotating bolts. Furthermore, the multiple connecting rods distributed outside the encapsulation tube provide some protection, reducing damage caused by external impacts and pressure, further ensuring the integrity and stability of the sensing structure. This provides strong support for the accuracy and reliability of multi-point distributed strain sensing using chirped phase-shift gratings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] Figure 2 This is a cross-sectional view of the overall structure of this utility model;

[0028] Figure 3 This is an exploded cross-sectional view of the overall structure of this utility model;

[0029] Figure 4 This is a schematic diagram of the structure of the outer end cover, the movable plate and the connecting rod of this utility model;

[0030] Figure 5 This is a cross-sectional view of the encapsulation tube, outer end cap, inner end cap, and optical cable of this utility model.

[0031] Figure 6 This is an exploded cross-sectional view of the encapsulation tube, outer end cap, and inner end cap of this utility model.

[0032] In the picture:

[0033] 1. Encapsulation tube, 101, inner shoulder;

[0034] 2. End seals;

[0035] 201. Outer end cap; 2011. Ear plate; 2012. Countersunk groove; 202. Inner end cap; 203. Through hole one; 204. Through hole two;

[0036] 3. Optical fiber cable; 4. Fiber optic grating;

[0037] 5. Sealing ring;

[0038] 6. Connecting rod; 7. Pressure plate;

[0039] 8. Optocoupler;

[0040] 9. Moving plate, 10. Connecting rod, 11. Bolt. Detailed Implementation

[0041] The present invention is illustrated below with specific embodiments, but these are not intended to limit the scope of the invention.

[0042] Example 1

[0043] like Figures 1-6 As shown in this embodiment, a sensitization structure for multi-point distributed strain sensing of chirped phase-shift gratings is provided, including a packaging tube 1. The packaging tube 1 is made of transparent glass and is a hollow structure with open ends. Both ends of the packaging tube 1 are respectively provided with end seals 2 for sealing the packaging tube 1. An optical cable 3 is disposed inside the packaging tube 1, with both ends of the optical cable 3 extending from the two end seals 2. The extended parts of the optical cable 3 are connected to an optocoupler 8. When the sensitization structure is working, the fiber optic grating 4 senses the strain change, and the optical signal is transmitted through the optical cable 3, coupled and transmitted through the optocoupler 8, to realize multi-point distributed strain sensing of chirped phase-shift gratings. The fiber optic grating 4 is disposed on the optical cable 3 and is encapsulated in the packaging tube 1.

[0044] Example 2

[0045] like Figures 2-6 As shown, based on Embodiment 1, in this embodiment, inner ring shoulders 101 are provided on the inner walls of both ends of the encapsulation tube 1, and the end seal 2 includes an outer end cap 201 and an inner end cap 202. The outer end cap 201 is inserted into the end of the encapsulation tube 1; the inner end cap 202 is installed inside the encapsulation tube 1 and abuts against the inner ring shoulder 101; wherein, when the outer end cap 201 and the inner end cap 202 are installed at the end of the encapsulation tube 1, there is a space between the outer end cap 201 and the inner end cap 202 for filling structural adhesive.

[0046] During installation, the inner end cap 202 is first installed on the end of the encapsulation tube 1. Then, structural adhesive is injected into the end of the encapsulation tube 1. Due to the restriction of the inner end cap 202, the structural adhesive will accumulate at the end of the encapsulation tube 1. Then, the outer end cap 201 is placed on the end of the encapsulation tube 1. At this time, the encapsulation tube 1 squeezes the structural adhesive. After the structural adhesive solidifies, it can seal the end of the encapsulation tube 1, improving the sealing effect.

[0047] The outer end cap 201 and the inner end cap 202 are respectively provided with through holes 203 and 204 for the optical cable 3 to pass through.

[0048] Both the through hole 203 and the outer wall of the outer end cap 201 are provided with threaded grooves. When the structural adhesive is squeezed by the outer end cap 201, the space between the outer end cap 201 and the inner end cap 202 gradually becomes smaller. The structural adhesive is squeezed, and the excess structural adhesive can enter the through hole 203 (the gap between the through hole 203 and the optical cable 3) and the gap between the outer wall of the outer end cap 201 and the encapsulation tube 1 along the threaded groove. After the structural adhesive solidifies, it can effectively seal the gap between the through hole 203 and the optical cable 3, and the gap between the outer end cap 201 and the encapsulation tube 1.

[0049] The interior of the second through hole 204 is provided with a sealing ring 5 for sealing the gap between the second through hole 204 and the optical cable 3; the outer wall of the sealing ring 5 is conical, and the shape of the second through hole 204 is adapted to the shape of the sealing ring 5; wherein, the side wall of the outer end cover 201 is connected to a pressure plate 7 by a connecting rod 6.

[0050] When the outer end cap 201 is installed at the end of the encapsulation tube 1, the pressure plate 7 presses the large end of the sealing ring 5, and the sealing ring 5 is pressed into the through hole 204, effectively sealing the gap between the through hole 204 and the optical cable 3, preventing structural adhesive from flowing into the encapsulation tube 1 from the gap.

[0051] Example 3

[0052] like Figure 1 and Figure 4 As shown in Embodiment 2, in this embodiment, multiple ear plates 2011 are circumferentially distributed on the sidewalls of the two outer end caps 201. A movable plate 9 is provided on the side of any outer end cap 201 away from the encapsulation tube 1. The movable plate 9 can move along the axis of the encapsulation tube 1. Multiple connecting rods 10 are distributed on the movable plate 9. One end of each connecting rod 10 passes through the ear plate 2011 on the same side of the outer end cap 201 and is fixed to the corresponding ear plate 2011 on the other outer end cap 201. Multiple bolts 11 are symmetrically engaged on the sidewall of the movable plate 9. The threaded ends of the multiple bolts 11 press against the outer end cap 201 on the same side. When the bolts 11 are rotated, the threaded ends of the bolts 11 press against one outer end cap 201 to move. At the same time, the movable plate 9 pulls the other outer end cap 201 to move through the connecting rods 10, so that the two outer end caps 201 can be installed at the same time. In addition, the multiple connecting rods 10 are distributed outside the encapsulation tube 1, which can play a certain protective role for the encapsulation tube 1 and prevent the encapsulation tube 1 from being damaged. A recess 2012 is provided on the outer end cover 201 near the movable plate 9 to limit the position of the threaded end of the bolt 11. The threaded end of the bolt 11 is pressed against the recess 2012 to prevent the threaded end of the bolt 11 from deflecting.

[0053] Work process:

[0054] When installing the sensitizing structure for multi-point distributed strain sensing of chirped phase-shift gratings, the inner end caps 202 are first installed at both ends of the encapsulation tube 1, with the inner end caps 202 abutting against the inner shoulder 101 to complete the initial positioning. Next, structural adhesive is injected into both ends of the encapsulation tube 1. Due to the restriction of the inner end caps 202, the structural adhesive accumulates at the ends of the encapsulation tube 1. Then, the outer end cap 201 is inserted into the ends of the encapsulation tube 1. At this time, a space for filling structural adhesive is formed between the outer end cap 201 and the inner end cap 202. As the outer end cap 201 is inserted, this space gradually decreases, and the structural adhesive is squeezed. Excess structural adhesive enters the gap between the through hole 203 and the optical cable, and the gap between the outer wall of the outer end cap 201 and the encapsulation tube 1, through the threaded groove on the through hole 203. After the structural adhesive solidifies, the ends of the encapsulation tube 1 are sealed. Simultaneously, during the installation of the outer end cap 201, the pressure plate 7 connected by the connecting rod 6 presses against the sealing ring 5, which is then pressed into the through hole 204, effectively sealing the gap between the through hole 204 and the optical cable, preventing structural adhesive from flowing into the encapsulation tube 1. Afterwards, the bolt 11 is rotated, and the threaded end of the bolt 11 presses against the recess 2012. As the bolt 11 rotates, the threaded end presses against the corresponding outer end cap 201, causing it to move. Simultaneously, the moving plate 9 pulls another outer end cap 201 via the connecting rod 10, allowing both outer end caps 201 to be installed simultaneously. Furthermore, multiple connecting rods 10 are distributed outside the encapsulation tube 1, providing a certain degree of protection for the encapsulation tube 1.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate and not limit the technical solutions of this utility model. Although this utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to this utility model without departing from the spirit and scope of this utility model. Any modifications or partial substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A sensitivity-enhancing structure for multi-point distributed strain sensing of chirped phase-shift gratings, characterized in that, include: The encapsulation tube (1) is a hollow structure with open ends; There are two end seals (2), which are respectively set at both ends of the encapsulation tube (1) and are used to encapsulate the encapsulation tube (1); Optical cable (3) is placed inside the encapsulation tube (1), and both ends of the optical cable (3) extend from the two end seals (2); Fiber Bragg grating (4) is mounted on optical cable (3) and encapsulated in encapsulation tube (1); The inner walls at both ends of the encapsulation tube (1) are provided with inner ring shoulders (101), and the end seals (2) include: The outer end cap (201) is inserted into the end of the encapsulation tube (1); The inner end cap (202) is installed inside the encapsulation tube (1) and abuts against the inner ring shoulder (101); When the outer end cap (201) and the inner end cap (202) are installed at the end of the encapsulation tube (1), there is a space between the outer end cap (201) and the inner end cap (202) for filling structural adhesive.

2. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 1, characterized in that, The outer end cap (201) and the inner end cap (202) are respectively provided with through holes one (203) and through holes two (204) for the optical cable (3) to pass through.

3. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 2, characterized in that, Both the through hole (203) and the outer wall of the outer end cap (201) are provided with threaded grooves.

4. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 2, characterized in that, The inside of the second through hole (204) is provided with a sealing ring (5) for sealing the gap between the second through hole (204) and the optical cable (3).

5. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 4, characterized in that, The outer wall of the sealing ring (5) is conical, and the shape of the through hole (204) is adapted to the shape of the sealing ring (5); Among them, a pressure plate (7) is connected to the side wall of the outer end cover (201) by a connecting rod (6); When the outer end cap (201) is installed at the end of the encapsulation tube (1), the pressure plate (7) presses against the large end of the sealing ring (5).

6. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 1, characterized in that, Multiple ear plates (2011) are distributed circumferentially on the sidewalls of the two outer end caps (201). A movable plate (9) is provided on the side of any outer end cap (201) away from the encapsulation tube (1). Multiple connecting rods (10) are distributed on the movable plate (9). One end of each connecting rod (10) passes through the ear plate (2011) on the same side outer end cap (201) and is fixed to the corresponding ear plate (2011) on the other outer end cap (201). Multiple bolts (11) are symmetrically meshed on the sidewall of the movable plate (9). The threaded ends of the multiple bolts (11) press against the same side outer end cap (201).

7. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 6, characterized in that, A groove (2012) is provided on the outer end cap (201) near the movable plate (9) to limit the position of the threaded end of the bolt (11).

8. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 1, characterized in that, The encapsulation tube (1) is made of transparent glass.

9. The sensitization enhancement structure for multi-point distributed strain sensing of chirped phase-shift gratings according to claim 1, characterized in that, An optocoupler (8) is connected to the optical cable (3).

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