Underwater pressure-resistant Fabry-Perot sensor packaging structure and method

Abstract

The invention provides an underwater pressure-resistant Fabry-Perot sensor packaging structure and method, the packaging structure comprises a front cap, a rear cap, silicone oil, a supporting seat, flexible foam particles and a Fabry-Perot sensor, the end face of the front cap is provided with a step shaft shoulder and a limiting groove, the step shaft shoulder is used for cooperating with the rear cap, and the limiting groove is used for cooperating with the positioning supporting seat; the front end of the rear cover cap is matched with the front cover cap in diameter, and is provided with a step shaft shoulder for being assembled with the supporting seat; the tail end of the rear cap is provided with a convex nozzle for protecting the led-out tail fiber; the silicone oil is used for filling the internal space of the front cap as a sound wave transmission coupling medium; the supporting seat is used for fixing the Fabry-Perot sensor between the front cap and the rear cap, and a pressure balance hole or a groove is formed in the supporting seat and used for communicating a cavity between the front cap and the rear cap; and the flexible foam particles are filled in the rear cover cap. According to the invention, the sensitive diaphragm part of the Fabry-Perot sensor is effectively protected, and the influence of external hydrostatic pressure change on the diaphragm of the Fabry-Perot sensor is reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing technology, and in particular to an underwater pressure-resistant Fabry-Perot sensor packaging structure and method. Background Art

[0002] Fabry-Perot sensors, as a high-precision fiber optic sensor, are widely used in many key fields such as aerospace, petrochemical, and environmental monitoring. These application environments often have extreme conditions, such as high pressure, high temperature, and corrosive media, which pose severe challenges to the stability and reliability of Fabry-Perot sensors. In these environments, sensors need to operate stably for a long time while maintaining high precision and high reliability to ensure the accuracy and validity of data.

[0003] In the practical application of Fabry-Perot sensors, the packaging structure of the probe is crucial. The packaging structure not only needs to protect the probe and the optical fiber connection from damage caused by stress concentration, but also needs to protect the sensitive diaphragm and the probe casing to prevent large particles of impurities from adhering to the surface of the sensitive diaphragm and affecting its sensitivity. When the Fabry-Perot sensor works in a deep-water pressure environment, it must be able to withstand a large static pressure and have a high acoustic test sensitivity, which becomes a technical difficulty. Summary of the invention

[0004] The present invention proposes a novel packaging structure of a Fabry-Perot sensor with a shell filled with a combination of flexible foam particles and silicone oil, and a packaging method thereof. The flexible foam particles are in the rear cover cap cavity in the shell, and the silicone oil is filled in the front cover cap cavity in the shell. When the sensor works in a deep-water pressure environment, the flexible foam particles can absorb the deformation pressure of the shell, so that the pressure in the shell of the Fabry-Perot sensor does not change significantly, and the fragile sensitive diaphragm of the Fabry-Perot sensor is effectively protected. At the same time, because the front cover cap cavity is filled with non-corrosive liquids such as silicone oil as a sound wave pressure transmission medium, it has a good acoustic impedance match with the cap, and the sensor has a lower sound wave transmission loss, maintaining a good sound wave test performance. The non-metallic front cap and lower cap used in the packaging structure have a streamlined shape, high compressive strength, and low flow noise.

[0005] According to a first aspect of the present invention, there is provided an underwater pressure-resistant Fabry-Perot sensor packaging structure, the packaging structure comprising a front cap, a rear cap, silicone oil, a support seat, flexible foam particles, and a Fabry-Perot sensor, wherein:

[0006] The end surface of the front cover cap is provided with a stepped shaft shoulder and a limiting groove, the stepped shaft shoulder is used to cooperate with the rear cover cap, and the limiting groove is used to cooperate with the positioning support seat;

[0007] The front end of the rear cap matches the diameter of the front cap, and is provided with a stepped shoulder for assembly with the support seat; the rear end of the rear cap has a protruding mouth for protecting the lead-out pigtail;

[0008] The silicone oil is used to fill the internal space of the front cap and serves as a coupling medium for acoustic wave transmission;

[0009] The support seat is used to fix the Fabry-Perot sensor between the front cap and the rear cap, and the support seat is provided with a pressure balance hole or a groove for connecting the cavity between the front and rear caps;

[0010] The flexible foam particles are filled in the rear cover cap, and the flexible foam particles are formed by thin-walled bubbles.

[0011] According to a second aspect of the present invention, there is provided a packaging method applicable to the above underwater pressure-resistant Fabry-Perot sensor packaging structure, comprising the following steps:

[0012] S1: Install the Fabry-Perot sensor in the support base, fit the tail end of the Fabry-Perot sensor into the V-groove of the support base, and fill the rear cap with flexible foam particles;

[0013] S2: Assemble the support base with the Fabry-Perot sensor and the rear cap, so that the Fabry-Perot sensor probe pigtail passes through the through hole of the rear cap, and the limit block of the support base is supported by the step shoulder in the rear cap and bonded with glue;

[0014] S3: Pour silicone oil into the front cap;

[0015] S4: Assemble the rear cap assembly completed in S2 and the front cap filled with silicone oil in S3, match the limit block of the support seat with the limit groove at the end of the front cap to ensure that the Fabry-Perot sensor is firmly positioned;

[0016] S5: Seal the interfaces of each part with waterproof sealant, including the front cap, rear cap interface and the interfaces between the Fabry-Perot sensor pigtail and the rear cap tail hole. Finally, wait for the sealant to dry thoroughly and test the performance of the Fabry-Perot sensor.

[0017] The beneficial effects of the present invention are:

[0018] The packaging structure of an underwater pressure-resistant Fabry-Perot sensor of the present invention is innovative and practical in design. Flexible foam particles and pressure balance holes are used for pressure balance, which effectively ensures the stability of the internal pressure of the sensor and significantly reduces the impact of external pressure fluctuations on the performance of the sensor. The streamlined front and rear cap designs not only reduce the interference of fluid dynamic noise, but also improve the reliability of the sensor in complex environments. The internally filled silicone oil and the polyurethane plastic shell have good acoustic impedance matching, effectively transmitting external sound waves to the Fabry-Perot sensor. The packaging structure provides long-term protection for the sensitive diaphragm and the optical fiber connection, avoiding impurity adhesion and stress concentration problems, thereby ensuring that the sensor can maintain high precision and stability for a long time in complex environments such as underwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A diagram showing the packaging structure of an underwater pressure-resistant Fabry-Perot sensor according to an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a Fabry-Perot sensor that needs to be protected according to an embodiment of the present invention;

[0021] FIG3 (a) is a schematic top view of a support base according to an embodiment of the present invention;

[0022] FIG3( b ) is a cross-sectional view of a support base according to an embodiment of the present invention;

[0023] Figure 4 is a schematic diagram of a front cover cap according to an embodiment of the present invention;

[0024] Figure 5 is a schematic diagram of a rear cover cap according to an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of an underwater pressure-resistant Fabry-Perot sensor packaging method according to an embodiment of the present invention.

[0026] Figure numerals: 1-front cover cap; 2-rear cover cap; 3-silicone oil; 4-support seat; 5-flexible foam particles; 6-Fabry-Perot sensor; 601-sensitive diaphragm; 602-Fabry-Perot sensor base; 603-pigtail connection; 604-Fabry-Perot sensor pigtail. DETAILED DESCRIPTION

[0027] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms, and the present disclosure should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0028] Figure 1 This is a diagram of the packaging structure of an underwater pressure-resistant Fabry-Perot sensor according to an embodiment of the present invention. Figure 1As shown, the packaging structure includes a front cap 1, a rear cap 2, silicone oil 3, a support seat 4, flexible foam particles 5 and a Fabry-Perot sensor 6, and the connection relationship between the various components is as follows: the end face of the front cap 1 is provided with a step shoulder and a limit groove, the step shoulder is used to cooperate with the rear cap 2, and the limit groove is used to cooperate with the positioning support seat 4. The front end of the rear cap 2 matches the diameter of the front cap 1, and has a step shoulder for assembly with the support seat 4; the rear end of the rear cap 2 has a protrusion for protecting the lead-out pigtail. Silicone oil 3 is used to fill the internal space of the front cap 1 as a coupling medium for sound wave transmission. The support seat 4 is used to fix the Fabry-Perot sensor 6 between the front cap 1 and the rear cap 2 to ensure the firmness of the probe packaging. There is a pressure balancing hole (or groove) on the support seat, which is used to connect the cavity between the front and rear caps and balance the pressure in the cavity of the front and rear caps; the flexible foam particles 5 are filled in the rear cap 2. The flexible foam particles are formed by a large number of thin-walled bubbles and have good compressibility. They can reduce the impact of hydrostatic pressure on the pressure in the cavity of the front and rear caps and protect the sensitive diaphragm.

[0029] In one embodiment, the shell material of the front cap 1 and the rear cap 2 includes but is not limited to polyurethane plastics; the selected plastic material does not produce chemical reactions with the application environment and can have good acoustic wave transmission impedance matching with the liquid. The front and rear caps are made of plastic materials, including but not limited to PP, PC, PS, PU, ​​ABS PVC, PTFE, etc. The front cap adopts a streamlined design, which can effectively reduce flow resistance.

[0030] Flexible foam particles are a structure formed by micro airbags and bubbles, which can be easily compressed by volume, including but not limited to polystyrene foam particles and polyethylene foam particles. Flexible foam particles contain a large number of bubbles and have good compressibility. It can reduce the impact of the volume deformation of the shell on the Fabry-Perot sensor diaphragm. When the external pressure causes the polyurethane plastic shell to deform slightly, the volume of the silicone oil liquid in the front cap is incompressible, and the silicone oil flows between the front and rear caps through the pressure balance hole. The volume of the flexible foam particles in the rear cap is reduced or increased, absorbing the volume deformation of the shell, and greatly reducing the pressure on the sensitive diaphragm of the Fabry-Perot sensor probe. This ensures the stable operation of the sensor in a pressurized liquid environment. The Fabry-Perot sensor with this packaging structure can be used in underwater environments at greater depths.

[0031] The application environment of the Fabry-Perot sensor 6 includes but is not limited to underwater environment, and can also be in other liquids. The above packaging structure is more capable of overcoming the static pressure caused by the liquid depth, or the application environment of the Fabry-Perot sensor 6 can be a closed container liquid pressure environment.

[0032] The silicone oil filled inside serves as the acoustic wave pressure transmission medium, which has good acoustic impedance matching with the plastic shell and can transmit external sound waves to the Fabry-Perot sensor with low loss.

[0033] Figure 2 The schematic diagram of the key components of the Fabry-Perot sensor that need to be protected according to an embodiment of the present invention includes a sensitive diaphragm 601, a Fabry-Perot sensor base 602, a pigtail connection 603 and a Fabry-Perot sensor pigtail 604. The sensitive diaphragm 601 is the core part of the sensor and is responsible for sensing the external sound wave pressure signal. The Fabry-Perot sensor base 602 provides support and fixation for the sensitive diaphragm and the optical fiber. The pigtail connection 603 is a protection point for the optical fiber leading out of the sensor. The Fabry-Perot sensor pigtail 604 is a transmission channel for the optical signal.

[0034] FIG3 (a) is a schematic top view of a support seat according to an embodiment of the present invention, and FIG3 (b) is a cross-sectional view of a support seat according to an embodiment of the present invention. The support seat 4 includes a V-groove, a stopper and a pressure balance hole. The V-groove of the support seat 4 is designed to accurately position the Fabry-Perot sensor probe to ensure its stability and reliability during the packaging process. The stopper is supported on the stepped shoulder of the rear cover cap to support and fix the probe, thereby preventing the probe from being displaced during operation, thereby ensuring the accuracy of the measurement results. In addition, a pressure balance hole is provided on the support seat to allow liquid to circulate and effectively stabilize the pressure inside the packaging structure.

[0035] Figure 4 The front cap is a schematic diagram of an embodiment of the present invention. It is designed as a streamlined structure to reduce liquid flow noise and improve the overall pressure resistance performance of the sensor. The bottom of the front cap is provided with a step and a limit groove. This design ensures precise matching with the support seat, thereby maintaining the stability of the Fabry-Perot sensor probe during the packaging process. Such a design can effectively reduce the flow noise generated by eddy currents and turbulence in the fluid flow.

[0036] Figure 5 Schematic diagram of the rear cap according to an embodiment of the present invention. The design of the rear cap is precisely matched with the front cap, and its diameter is suitable for close assembly with the front cap. During the packaging process, the interior of the rear cap is filled with flexible foam particles, which can absorb the pressure changes caused by the deformation of the shell, thereby helping to maintain the pressure inside the packaging structure stable. In addition, a pigtail lead-out hole is provided at the end of the rear cap to allow the sensor pigtail to be led out and connected externally.

[0037] Figure 6 Schematic diagram of the packaging method of an underwater pressure-resistant Fabry-Perot sensor according to an embodiment of the present invention. Figure 6 Describe the packaging method. Figure 6 As shown, the packaging method in this embodiment adopts the following steps S1-S5. Each step is described in detail below.

[0038] In step S1, the Fabry-Perot sensor is placed in the support base, and the tail end of the sensor is ensured to fit tightly with the V-groove of the support base, and flexible foam particles are filled in the rear cover cap.

[0039] In step S2, the support base with the Fabry-Perot sensor is assembled with the rear cap, so that the Fabry-Perot sensor tail fiber passes through the rear hole of the rear cap, and the limit block of the support base is supported on the step shoulder of the rear cap and fixed with glue.

[0040] In step S3, silicone oil is poured into the front cap 1 to ensure that the interior thereof is filled with the sound wave transmission medium.

[0041] In step S4, the assembled rear cap and the front cap filled with silicone oil are combined, and the limit block of the support seat placed in the rear cap is inserted into the limit groove of the front cap to stabilize the position of the Fabry-Perot sensor and prevent displacement.

[0042] Finally, in step S5, all interfaces are sealed with waterproof sealant, including the interfaces of the front and rear caps and the tail hole of the sensor pigtail and the rear cap, to ensure the waterproofness and sealing of the overall structure. After the sealant is completely dry, the Fabry-Perot sensor performance test is performed.

[0043] In summary, the invention provides an underwater pressure-resistant Fabry-Perot sensor packaging structure and a packaging method thereof. The packaging steps include but are not limited to those described in the above embodiments. The packaged Fabry-Perot sensor needs to be subjected to performance testing to verify the safety and detection performance of the sensor itself.

[0044] The present invention aims to improve the ability of the Fabry-Perot sensor to withstand hydrostatic pressure without reducing its sensitivity. The packaging structure includes a front cap, a rear cap, silicone oil, a support seat, flexible foam particles and a Fabry-Perot sensor. The packaging structure adopts a closed streamlined shell and can withstand a large hydrostatic pressure. The flexible foam particles filled in the rear cap have good volume compressibility, can absorb the volume deformation of the shell under hydrostatic pressure, stabilize the pressure inside the shell, and play a good protective role on the sensitive diaphragm of the Fabry-Perot sensor. At the same time, the silicone oil filled in the front cover and between the sensor diaphragm has good sound transmission characteristics due to the matching of acoustic impedance, thereby ensuring the sensitivity of the sensor. The present invention effectively protects the sensitive diaphragm part of the Fabry-Perot sensor, reduces the influence of external hydrostatic pressure changes on the Fabry-Perot sensor diaphragm, and while enhancing the hydrostatic pressure resistance of the Fabry-Perot sensor, does not reduce the test performance of the diaphragm to sound waves, thereby broadening the underwater application space of the Fabry-Perot sensor.

[0045] Obviously, the above embodiments are only examples for clear explanation and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description, and the changes or modifications derived therefrom are still within the protection scope of the invention.

Claims

1. An underwater pressure-resistant Fabry-Perot sensor packaging structure, characterized in that: The packaging structure comprises a front cover cap (1), a rear cover cap (2), silicone oil (3), a support seat (4), flexible foam particles (5), and a Fabry-Perot sensor (6), wherein: The end surface of the front cover cap (1) is provided with a stepped shaft shoulder and a limiting groove, the stepped shaft shoulder is used to cooperate with the rear cover cap (2), and the limiting groove is used to cooperate with the positioning support seat (4); The front end of the rear cover cap (2) matches the diameter of the front cover cap (1), and is provided with a stepped shoulder for assembly with the support seat (4); the rear end of the rear cover cap has a protruding mouth for protecting the lead-out pigtail; The silicone oil (3) is used to fill the internal space of the front cover cap (1) and serves as a coupling medium for acoustic wave transmission; The support seat (4) is used to fix the Fabry-Perot sensor (6) between the front cover cap (1) and the rear cover cap (2), and a pressure balance hole or groove is provided on the support seat to connect the cavity between the front and rear cover caps; The flexible foam particles (5) are filled in the rear cover cap (2), and the flexible foam particles are formed by thin-walled bubbles.

2. The underwater pressure-resistant Fabry-Perot sensor packaging structure according to claim 1, characterized in that: The outer shell materials of the front cover cap and the rear cover cap include polyurethane plastics.

3. The underwater pressure-resistant Fabry-Perot sensor packaging structure according to claim 1, characterized in that: The front cap adopts a streamlined design.

4. The underwater pressure-resistant Fabry-Perot sensor packaging structure according to claim 1, characterized in that: Flexible foam particles include polystyrene foam particles and polyethylene foam particles.

5. The underwater pressure-resistant Fabry-Perot sensor packaging structure according to claim 1, characterized in that: The support seat includes a V-shaped groove and a limit block. The V-shaped groove is designed to position the Fabry-Perot sensor probe, and the limit block is supported on the step shoulder of the rear cover cap.

6. A method for packaging an underwater pressure-resistant Fabry-Perot sensor, applicable to the underwater pressure-resistant Fabry-Perot sensor packaging structure according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Install the Fabry-Perot sensor in the support seat (4), fit the rear end of the Fabry-Perot sensor into the V-groove of the support seat, and fill the rear cover cap (2) with flexible foam particles (5); S2: Assemble the support base with the Fabry-Perot sensor and the rear cover (2), so that the Fabry-Perot sensor pigtail (604) passes through the through hole of the rear cover (2), and the limit block of the support base (4) is supported by the step shoulder in the rear cover (2), and glued together; S3: Pour silicone oil into the front cap (1); S4: Assemble the rear cap assembly completed in S2 and the front cap (1) filled with silicone oil in S3, match the limit block of the support seat (4) with the limit groove at the end of the front cap to ensure that the Fabry-Perot sensor is firmly positioned; S5: Seal the interfaces of each part with waterproof sealant, including the front cap, rear cap interface and the interfaces between the Fabry-Perot sensor pigtail and the rear cap tail hole. Finally, wait for the sealant to dry thoroughly and test the performance of the Fabry-Perot sensor.

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