Optical fiber gyroscope and assembling method thereof

Abstract

The invention relates to the technical field of gyroscopes, and discloses an optical fiber gyroscope and an assembling method thereof. And the optical fiber gyroscope is an optical fiber gyroscope of which the temperature control circuit board is connected with a fully integrated optical system. The fully integrated optical system has a plurality of pins. A flexible wire electrically connected with the temperature control circuit board is arranged on the outer edge of the temperature control circuit board. The flexible wire is provided with connecting holes, the number of the connecting holes is equal to that of the pins, the distance between the connecting holes is equal to that between the pins, and the diameter of the connecting holes is larger than that of circumcircles of the pins. In an assembly state, after the flexible wire is bent according to a matched bending radius, each pin is inserted into the corresponding connecting hole in space, and then the pins and the flexible wire are welded together. And under the condition that the space is extremely limited, the assembly of the optical fiber gyroscope is completed with high efficiency, high precision and high quality, so that the stability of the overall structure of the optical fiber gyroscope is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of gyroscopes, and in particular relates to an optical fiber gyroscope and an assembly method thereof. Background Art

[0002] An optical fiber gyroscope is an inertial navigation instrument widely used in modern aviation, navigation, aerospace and other fields. In-depth research on optical fiber gyroscopes is of great significance for the development of a country's core technologies such as industry and national defense.

[0003] An optical fiber gyroscope has a significant advantage of small volume compared with traditional mechanical gyroscopes. However, with the development of miniaturization and microminiaturization in fields such as unmanned aerial vehicles and weaponry, the volume requirements for optical fiber gyroscopes are also more stringent. Therefore, the research focus of the existing technology on optical fiber gyroscopes is on how to develop an optical fiber gyroscope with a more compact structure and smaller volume.

[0004] As the volume of the optical fiber gyroscope is further reduced, the operating space in the optical assembly, electrical assembly and mechanical assembly processes is further compressed. When the assembly process provided by the existing technology is applied to an actual scenario with limited space, it will lead to problems that the assembly accuracy and assembly efficiency cannot meet the requirements. Moreover, more seriously, the connection strength or structural stability of the optical fiber gyroscope after assembly is adversely affected. Since optical fiber gyroscopes are mostly used in extremely harsh environments such as high speed, high acceleration, high impact, high vibration and large temperature difference, there are extremely high requirements for the connection strength between its components and the overall structural stability. In view of this, there is an urgent need to propose a process that can efficiently, accurately and high-quality complete the assembly of an optical fiber gyroscope under extremely limited space, as well as a high-precision and high-strength optical fiber gyroscope manufactured by applying this process. Summary of the Invention

[0005] The purpose of the present invention is to provide an optical fiber gyroscope and a manufacturing method thereof, which can efficiently, accurately and high-quality complete the assembly of the optical fiber gyroscope under extremely limited space, so as to ensure the stability of the overall structure of the optical fiber gyroscope.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides an optical fiber gyroscope, which is an optical fiber gyroscope with a fully integrated optical system connected to a temperature-controlled circuit board. The fully integrated optical system has a plurality of pins. An extension of the temperature-controlled circuit board is provided with a flexible wire electrically connected thereto. The flexible wire is provided with connection holes, the number of connection holes is equal to the number of pins, the pitch between the connection holes is equal to the pitch of the pins, and the diameter of the connection holes is larger than the diameter of the flexible wire. In the assembled state, after the flexible wire is bent according to a matching bending radius, each pin is inserted into the connection hole corresponding to it in space, and then the pin is welded to the flexible wire.

[0008] As a possible implementation, a plurality of pads are arranged at intervals on the flexible wire, the connection holes are opened on the pads, and the connection holes are through holes penetrating the flexible wire.

[0009] As a possible implementation, the flexible wire includes an insulating layer and a conductive wire. The material of the insulating layer at least includes TPC, PVC, PUR or silicone, the material of the conductive wire is copper foil, and the pads are made by an immersion gold process.

[0010] As a possible implementation, the outer diameter of the circumcircle of the pin is d, and the diameter of the connection hole is d + 0.1 mm to d + 0.2 mm.

[0011] As a possible implementation, there are two flexible wires, symmetrically and integrally arranged on both sides of the temperature-controlled circuit board; each flexible wire includes a connection section and a welding section, and the pads are arranged on the welding section;

[0012] Wherein, one end of the connection section is connected to the temperature-controlled circuit board, the other end of the connection section is vertically and integrally connected to the welding section, and there is a space for avoiding interference between the inner side of the welding section and the temperature-controlled circuit board.

[0013] As a possible implementation, the optical fiber gyroscope further includes: a base, the bottom of the base is fixedly connected with a control circuit board, and a lower cover is fixedly connected to the bottom of the base to seal the control circuit board; the temperature-controlled circuit board is fixed on the convex table surface at the top of the base, and the connector of the temperature-controlled circuit board is inserted into the control circuit board; the fully integrated optical system is fixed on the top of the convex table surface;

[0014] A shielding cavity is tightly connected to the position of the base surrounding the fully integrated optical system; an optical fiber ring is fixedly arranged in the cavity of the shielding cavity; the top of the shielding cavity is tightly connected with a shielding cover, and a wire outlet groove for leading out the tail fiber of the optical fiber ring is opened on the shielding cover; the tail fiber of the optical fiber ring is led out from the wire outlet groove and fused with the tail fiber of the fully integrated optical system; an upper cover is fixed on the shielding cover.

[0015] As a possible implementation, the tail fiber of the optical fiber ring and the tail fiber of the fully integrated optical system are on the same horizontal plane, or have a height difference, and the height difference is not greater than 1 / 10 of the bending radius of the tail fiber of the optical fiber ring.

[0016] As a possible implementation, a plurality of heat insulation pads are equidistantly arranged between the optical fiber ring and the inner wall of the shielding cavity, and the inner wall of the optical fiber ring is adhesively bonded to the outer wall of the heat insulation pad, and the inner wall of the heat insulation pad is adhesively bonded to the inner wall of the shielding cavity.

[0017] As a possible implementation, the surface of the fully integrated optical system in contact with the convex table surface is defined as a heat conducting surface, and heat conducting silicone grease is applied on the heat conducting surface.

[0018] In a second aspect, the present invention further provides an assembling method for an optical fiber gyroscope, including the following steps:

[0019] Provide a base, fixedly connect a control circuit board to the bottom of the base, fix a lower cover to the bottom of the base to seal the control circuit board; fix a temperature control circuit board on the convex table surface at the top of the base; insert the connector of the temperature control circuit board into the control circuit board in an opposing manner; fix the fully integrated optical system on the top of the convex table surface, insert the pins into the flexible wires on the temperature control circuit board in an opposing manner and then perform spot welding;

[0020] Provide a shielding cavity, fix the optical fiber ring in the cavity of the shielding cavity, and cover the shielding cover on the top of the shielding cavity, and lead out the tail fiber of the optical fiber ring from the wire outlet groove opened on the shielding cover;

[0021] Fasten and connect the shielding cavity to the position of the base surrounding the fully integrated optical system;

[0022] Fuse the tail fiber of the optical fiber ring with the tail fiber of the fully integrated optical system.

[0023] Compared with the prior art, the present invention has the following effects:

[0024] 1. The temperature control circuit board of the optical fiber gyroscope is connected with an integrated optical system. On the basis of improving the integration degree of the optical fiber gyroscope, the volume is further reduced to meet the application requirements of its miniaturization.

[0025] Due to the high integration degree of the integrated optical system, the number of pins on it is large and more dense. In the case where the assembly space of the fully integrated optical system is extremely limited, the welding between the large number of more dense pins and the temperature control circuit board becomes extremely difficult. In other words, the traditional welding method leads to a complex welding process and is prone to cause the failure of the function of the fully integrated optical system due to the low welding reliability of the dense pins.

[0026] In the present invention, a flexible wire electrically connected to a temperature-controlled circuit board is provided on the extension thereof, and connection holes corresponding to the pins one by one in space are processed on the flexible wire. During assembly, taking advantage of the bendable property of the flexible wire, first, according to the actual working space and the positional relationship between the connection holes and the pins, the matching bending radius of the flexible wire is determined. Then, after bending the flexible wire according to the matching bending radius, the pins are inserted into the corresponding connection holes one by one to achieve the preliminary positioning of the pins. Finally, the pins and the connection holes are firmly welded using a welding process to achieve stable welding between the pins and the connection holes.

[0027] As can be seen from the above assembly process, raising the welding position from the temperature-controlled circuit board can improve the welding convenience and thus the welding efficiency in an extremely limited space. Moreover, by applying the connection holes on the flexible wire to connect the flexible wire and the pins in an assembly manner of first positioning and then fastening, the fastening degree and stability of the connection between the two can be ensured. In addition, when the pins are inserted into the connection holes, the flexibility of the flexible wire can be used to maximally eliminate the stress between the pins and the connection holes. Under the action of external factors such as temperature, vibration, and shock, the above stress will cause certain damage to the fiber optic gyroscope itself over time and even lead to its failure, seriously affecting the product reliability and stability. Based on this, after the pins are welded to the flexible wire, problems such as fracture of the welding point due to stress concentration can be effectively avoided, thereby ensuring the stability of the fiber optic gyroscope during application.

[0028] In summary, the fiber optic gyroscope provided by the present invention can efficiently, accurately, and with high quality complete the assembly of the fiber optic gyroscope in an extremely limited space, thereby ensuring the stability of the overall structure of the fiber optic gyroscope.

[0029] 2. Applying the connection method of the pins of the fully integrated optical system provided by the present invention to the connection holes of the flexible wire of the temperature-controlled circuit board, compared with the traditional wire welding method (such as directly welding on the temperature-controlled circuit board in real time), while giving full play to the advantages of the flexible wire, it efficiently utilizes the limited internal space, reduces the overall size of the fiber optic gyroscope, and further promotes the development of miniaturization and integration of the fiber optic gyroscope.

[0030] 3. Adopting an immersion gold process on the flexible wire to form solder pads with a hardness higher than that of the flexible wire is equivalent to setting reinforcement pieces. When the pins are connected to the connection holes opened on the solder pads, it is not only convenient for welding but also can ensure the firmness after welding, thereby ensuring the stability of the connection.

[0031] 4. The present invention has greatly optimized the assembly process, changing from the traditional serial assembly process to a way in which different components can be assembled in parallel, meeting the requirements of mass production. Each component module is both independent and cooperative with each other, and has great convenience and economy in subsequent maintenance. Brief Description of the Drawings

[0032] The drawings described herein are provided to further understand the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0033] Figure 1 It is a schematic structural diagram of the temperature control circuit board provided by the embodiment of the present invention;

[0034] Figure 2 It is a schematic structural diagram of the fully integrated optical system provided by the embodiment of the present invention;

[0035] Figure 3 It is a schematic overall structural diagram of the fiber optic gyroscope in the assembled state provided by the embodiment of the present invention;

[0036] Figure 4 It is a schematic cross-sectional view of the fiber optic gyroscope in the assembled state provided by the embodiment of the present invention;

[0037] Figure 5 It is an exploded view of the fiber optic gyroscope provided by the embodiment of the present invention;

[0038] Figure 6 It is a flowchart of the assembly method of the fiber optic gyroscope provided by the embodiment of the present invention.

[0039] Reference Numerals

[0040] 1 - Temperature control circuit board, 10 - Flexible wire, 11 - Connection hole, 12 - Pad, 100 - Connection section, 101 - Welding section;

[0041] 2 - Fully integrated optical system, 20 - Pin;

[0042] 3 - Base;

[0043] 4 - Control circuit board;

[0044] 5 - Lower cover;

[0045] 6 - Shielding cavity;

[0046] 7 - Fiber optic loop;

[0047] 8 - Upper cover;

[0048] 9 - Shielding cover. Detailed Description of the Embodiments

[0049] For the convenience of clearly describing the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, terms such as "first" and "second" are used to distinguish identical or similar items with basically the same functions and roles. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not limit their sequence. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different.

[0050] It should be noted that in the present invention, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0051] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c, where a, b, and c can be single or multiple.

[0052] See Figure 1 and Figure 2 , the fiber optic gyroscope provided by the embodiment of the present invention is a fiber optic gyroscope in which a fully integrated optical system 2 is connected to a temperature-controlled circuit board 1.

[0053] Among them, the fully integrated optical system 2 can be a four-in-one fully integrated optical system, which specifically means that on a single substrate, through advanced micro-nano processing technology, multiple optical elements, such as lasers, detectors, thin-film lithium phosphate Y waveguides, couplers, etc., and possible electronic elements (such as transistors, resistors, capacitors, etc.) are integrated together to form an optical system with specific functions, that is, an optical system integrating functions such as light source emission, beam splitting, polarization control, modulation, and photoelectric detection. Such a system can realize functions such as generation, transmission, processing, and detection of optical signals, and has the advantages of small volume, low power consumption, and stable performance.

[0054] The fully integrated optical system 2 has multiple pins 20. The temperature control circuit board 1 is externally provided with a flexible wire 10 electrically connected thereto.

[0055] As an example, N pins 20 are symmetrically distributed on the left and right sides of the fully integrated optical system 2, where N≥5. At this time, a flexible wire 10 is correspondingly provided on each of the left and right sides of the temperature control circuit board 1. N connection holes 11 are formed in each flexible wire 10. The number of connection holes 11 is equal to the number of pins 20, and the pitch between the connection holes 11 is equal to the pitch between the pins 20. The diameter of the connection hole 11 is larger than the diameter of the circumcircle of the pin 20. As an example, the diameter of the circumcircle of the pin is d, and the diameter of the connection hole is d + 0.1 mm to d + 0.2 mm. For example, when the diameter of the circumcircle of the pin 20 is 0.4 mm, the diameter of the connection hole 11 can be 0.45 mm, 0.5 mm, 0.55 mm or 0.6 mm to facilitate the insertion of the pin 20 into the connection hole 11.

[0056] In the assembled state, after the flexible wire 10 is bent according to the matching bending radius, each pin 20 is inserted into the connection hole 11 corresponding to it in space, and then the pin 20 is welded to the flexible wire.

[0057] It should be noted that the matching bending radius is determined according to the actual space, the length of the flexible wire 10 and the positional relationship with the pin 20, and no specific limitation is made here. For example, when the space is small, the length of the flexible wire 10 is short and the position relative to the pin 20 is far, the matching bending radius can be relatively large.

[0058] In practical applications, the fully integrated optical system 2 is integrated on the fiber optic gyroscope. On the basis of improving the integration level of the fiber optic gyroscope, the volume is further reduced to meet the application requirements of miniaturization. The overall external dimensions of the fiber optic gyroscope provided by the embodiment of the present invention are 50 mm (L) × 50 mm (W) × 24 mm (H). The optical transceiver and processing module is highly integrated, and each component is independent of each other and tightly connected. The further reduced volume makes the space inside the shielding cavity 6 of the fiber optic gyroscope smaller. Moreover, since the fully integrated optical system 2 integrates multiple functions, the number of pins 20 on the fully integrated optical system 2 is numerous and within the effective space, the size of the pins 20 is smaller and the distribution is more intensive. In view of this, when the assembly space of the fully integrated optical system 2 is extremely limited, the welding between the numerous and more intensive pins 20 and the temperature control circuit board 1 becomes extremely difficult. In other words, the traditional welding method results in a complex welding process and is likely to cause the failure of the functions of the fully integrated optical system 2 due to the low welding reliability of the intensive pins 20. At this time, a flexible wire 10 electrically connected to the temperature control circuit board 1 is provided on the extension of the temperature control circuit board 1, and connection holes 11 corresponding to the pins 20 in space are processed on the flexible wire 10. During assembly, by utilizing the property of the flexible wire 10 being easy to bend, first, according to the actual working space and the positional relationship between the connection holes 11 and the pins 20, the matching bending radius of the flexible wire 10 is determined. Then, after bending the flexible wire 10 according to the matching bending radius, the pins 20 are inserted into the corresponding connection holes 11 one by one to achieve the preliminary positioning of the pins 20. Finally, the pins 20 and the connection holes 11 are firmly welded by using the welding process to achieve the fastening of the pins 20 and the connection holes 11. From the above assembly process, it can be seen that by raising the welding position from the temperature control circuit board 1, the welding convenience can be improved within the extremely limited space, thereby improving the welding efficiency. Moreover, by applying the connection holes 11 on the flexible wire 10 to adopt an assembly method of positioning first and then fastening, the connection between the flexible wire 10 and the pins 20 can be realized, and the firmness and stability of the connection between the two can be ensured. In addition, when the pins 20 are inserted into the connection holes 11, the flexibility of the flexible wire 10 can be used to eliminate the stress between the pins 20 and the connection holes 11 to the greatest extent. Under the action of external factors such as temperature, vibration, and shock, the above stress will cause certain damage to the fiber optic gyroscope itself over time and even lead to its failure, seriously affecting the reliability and stability of the product. Based on this, when the pins 20 are welded to the flexible wire 10, problems such as the fracture of the welding point due to stress concentration can be effectively avoided, thereby ensuring the stability of the fiber optic gyroscope during application. In summary, the fiber optic gyroscope provided by the present invention can complete the assembly of the fiber optic gyroscope efficiently, with high precision and high quality under the condition of extremely limited space, thereby ensuring the stability of the overall structure of the fiber optic gyroscope.

[0059] In addition, the connection method between pin 20 of the fully integrated optical system 2 provided by the present invention and the flexible wire connection hole 11 of the temperature control circuit board, compared with the traditional wire soldering method (such as directly soldering in real time on the temperature control circuit board), on the basis of giving full play to the advantages of the flexible wire 10, efficiently utilizes the limited internal space, reduces the overall size of the fiber optic gyroscope, and further promotes the development of miniaturization and integration of the fiber optic gyroscope.

[0060] To facilitate bending the flexible wire 10 with an arbitrary matching bending radius, it is required that the flexible wire 10 has good flexibility, that is, relatively weak hardness. When pin 20 is directly soldered to the flexible wire, the soldering effect cannot reach the optimal effect. In view of this, in the embodiment of the present invention, a plurality of pads 12 with a certain hardness are arranged at intervals on the flexible wire 10, the connection hole 11 is opened on the pad 12, and penetrates the flexible wire 10 below the pad 12. At this time, after pin 20 is inserted into connection hole 11, the hardness of pad 12 can make the two have good connection strength, that is, after connection, the flexible wire 10 is not easily separated from pin 20. Moreover, after preliminary positioning connection, the pad 12 with a certain hardness makes soldering easier, and the soldering efficiency and soldering effect are better.

[0061] To balance the conductivity and flexibility of the flexible wire 10, the flexible wire 10 includes an insulating layer and a conductive wire. The material of the insulating layer at least includes TPC, PVC, PUR or silicone, and the material of the conductive wire is copper foil. The flexible wire 10 and the temperature control circuit board 1 are integrally processed. The pad 12 can be formed by applying an immersion gold process on the flexible wire.

[0062] From a structural perspective, each flexible wire 10 includes a connection section 100 and a welding section 101, and the pad 12 is arranged on the welding section 101. Among them, one end of the connection section 100 is connected to the temperature control circuit board 1, the other end of the connection section 100 is vertically and integrally connected to the welding section 101, and there is a space to avoid interference between the inner side of the welding section 101 and the temperature control circuit board 1.

[0063] As an example, both the connection section 100 and the welding section 101 are strip-shaped structures with an approximately rectangular cross-section, and as a whole, they are in an L-shaped structure rotated 90° clockwise.

[0064] See Figures 3 to 5 , the fiber optic gyroscope provided by the embodiment of the present invention further includes a base 3. The bottom of the base 3 is fixedly connected to a control circuit board 4, and a lower cover 5 is fixedly connected to the bottom of the base 3 to seal the control circuit board 4.

[0065] The structure of the base 3 is basically the same as that of the fiber optic gyroscope provided by the prior art, and will not be elaborated here. The connection method between the base 3 and the control circuit board 4 can be screw connection.

[0066] The temperature control circuit board 1 is fixed on the convex surface on the top of the base 3, and the connector of the temperature control circuit board 1 is plugged into the control circuit board 4; the fully integrated optical system 2 is fixed on the top of the convex surface.

[0067] The shielding cavity 6 is fastened to the base 3 at a position located outside the fully integrated optical system 2; the optical fiber ring 7 is fixedly arranged in the cavity of the shielding cavity 6; the top of the shielding cavity 6 is fastened to the shielding cover 9, and the shielding cover 9 is provided with an outlet groove for leading out the pigtail of the optical fiber ring 7; the pigtail of the optical fiber ring 7 is led out from the outlet groove and fused with the pigtail of the fully integrated optical system 2; the upper cover 8 is fixed on the shielding cover 9.

[0068] The fiber optic gyroscope provided in the embodiment of the present invention is a fiber optic ring 7, an integrated optical system, a control circuit board 4, a temperature control circuit board 1 and other main components, which are organized and closely arranged together, so that the product volume is further reduced, so that it can be better assembled in small or micro drones, medium and short-range cruise missiles and other small spaces. Each component cooperates closely and is independently partitioned and does not affect each other, which ensures that the product has extremely high stability and has broad market application prospects.

[0069] The optical fiber ring 7 is wound by a long optical fiber in a circular ring shape, with two optical fiber pigtails facing outward. The pigtail of the fully integrated optical system 2 is fused with the pigtail of the optical fiber ring 7 to form a complete optical path. In addition, the fully integrated optical system 2 is connected to the flexible wire 10 socket of the temperature control circuit board 1 by spot welding and fixation to perform preliminary sorting and analysis on the optical signal received and sent by the former, and then realizes the connection with the control circuit through the connector of the control circuit board 4, so as to further integrate and analyze the signal sent by the temperature control circuit, and finally convert it into the required signal for output. The above is the basic working principle of the optical fiber gyroscope provided by the embodiment of the present invention.

[0070] As a possible implementation, the base 3, the lower cover 5 and the upper cover 8 are made of at least aluminum, copper, magnesium, silicon, zinc, manganese, titanium, nickel and iron. The tensile strength is 410Mpa to 470Mpa, the yield strength is 265Mpa to 325Mpa, the elongation is 10% to 12%, and the density is 2.71g / cm 3 , thermal conductivity is 120~135W / (m·K), Brinell hardness is 120N / mm 2 .

[0071] As an example, the base 3, the lower cover 5 and the upper cover 8 are made of aluminum alloy 2A12-T4 after anodizing treatment. The base 3, the lower cover 5 and the upper cover 8 included in the fiber optic gyroscopes provided by the prior art generally adopt traditional 5-series or 6-series aluminum alloys, which have the advantages of high strength, corrosion resistance, easy processing and light weight. For example, the tensile strength of the 5-series aluminum alloy is 240 Mpa - 280 Mpa, the yield strength is 110 Mpa - 130 Mpa, the density is 2.66 g / cm 3 , the elongation rate is 12% - 25%, the thermal conductivity is 156 W / (m·K), and the Brinell hardness is 70 N / mm 2 -95 N / mm 2 . Also, for example, the tensile strength of the 6-series aluminum alloy is 290 Mpa - 395 Mpa, the yield strength is 240 Mpa - 310 Mpa, the density is 2.75 g / cm 3 , the elongation rate is 8% - 16%, the thermal conductivity is 167 W / (m·K) - 180 W / (m·K), and the Brinell hardness is 95 N / mm 2 -100 N / mm 2 .

[0072] In addition to the above advantages, the aluminum alloy 2A12-T4 applied in the embodiments of the present invention is more excellent in terms of strength. Specifically, its tensile strength is 410 Mpa - 470 Mpa, the yield strength is 265 Mpa - 325 Mpa, the elongation rate is 10% - 12%, and the density is 2.71 g / cm 3 , the thermal conductivity is 120 - 135 W / (m·K), and the Brinell hardness is 120 N / mm 2 . That is, the aluminum alloy 2A12-T4 can meet the use of the fiber optic gyroscope in relatively harsh environments such as high speed, high acceleration, high impact, strong vibration, and large temperature difference.

[0073] After the salt spray test, the corrosion grade of 5083 aluminum alloy after 90 days of exposure is C5M level. The corrosion grade of 6063 aluminum alloy after 90 days of exposure is C3 level. After the salt spray test, the corrosion grade of 6061-T6 aluminum alloy after 90 days of exposure is C4 level. It can be seen that the corrosion resistance of 5083 is relatively superior. The embodiments of the present invention make the aluminum alloy 2A12-T4 have salt spray and corrosion resistance capabilities not inferior to those of materials such as 5083 through anodizing treatment or painting treatment.

[0074] Based on the above analysis, the present invention uses 2A12-T4 aluminum alloy as the material for the base 3, the lower cover 5, and the upper cover 8. The most prominent feature is its high strength and light weight, making it easy to process. Although its thermal conductivity is slightly inferior to that of 5083 and 6061, it fully meets the usage requirements when the heat dissipation power of the device is not large and the heat dissipation method and path are reasonably optimized. Additionally, by performing anodic oxidation treatment or painting on its surface, its corrosion resistance is not inferior to that of 5083.

[0075] The optical fiber ring 7 is the core of the optical fiber ring 7 component with optical transceiver. The optical path transmission of the fiber optic gyroscope is significantly interfered by the ambient magnetic field. Therefore, magnetic shielding is required. To achieve a better magnetic shielding effect, some materials with excellent magnetic permeability and magnetic saturation induction intensity can be selected. For example, ferrite materials are an optional choice. It can effectively isolate the influence of the external magnetic field due to its high magnetic permeability and magnetic saturation induction intensity. In addition, soft magnetic alloy materials are also a candidate. It not only has good magnetic conductivity but also can absorb the energy of the external magnetic field and reduce the influence range of the magnetic field.

[0076] As a possible implementation, the composition of the shielding cover 9 and the shielding cavity 6 materials includes at least iron, nickel, silicon, manganese, phosphorus, sulfur, cobalt, and chromium. The saturation magnetic induction intensity of the shielding cover 9 and the shielding cavity 6 is 1.55T - 1.60T, and the initial magnetic permeability (μi) and the maximum magnetic permeability (μmax) are 20000H / m - 30000H / m and 50000H / m - 70000H / m respectively. The coercive force (Hc) is 0.4A / m - 0.6A / m.

[0077] As an example, the shielding cover 9 and the shielding cavity 6 are machined from the 1J85 material of iron-nickel alloy and are subjected to high-temperature annealing (hydrogen protection) treatment. The 1J85 alloy is a high-nickel iron alloy, mainly containing elements such as iron, nickel, cobalt, copper, and manganese. The high nickel content endows the material with excellent magnetic properties. The addition of cobalt further improves the magnetic stability of the alloy. And copper enhances its electrical conductivity. Through high-temperature annealing treatment, its magnetic and mechanical properties are significantly improved, showing low hysteresis loss. In addition, the material has nearly zero magnetoelasticity and significant anisotropic magnetoresistance. In terms of mechanical properties, the annealed 1J85 has good tensile strength and is superior in terms of the toughness and plasticity of the material, making it suitable for the manufacture of parts with complex shapes and high strength requirements.

[0078] Based on the above advantages, 1J85 is widely used in many fields such as aerospace, precision instruments, automation control, and weaponry. Therefore, it is relatively reliable to select this material as the peripheral protective layer of the optical fiber ring 7.

[0079] As a possible implementation, the pigtail of the optical fiber loop 7 and the pigtail of the fully integrated optical system 2 are located on the same horizontal plane, or have a height difference that is not greater than 1 / 10 of the bending radius of the pigtail of the optical fiber loop. With such a setting, a natural transition from the pigtail of the fully integrated optical system 2 to the pigtail of the optical fiber loop 7 can be achieved, reducing stress concentration and preventing the optical fiber loop 7 from breaking.

[0080] It should be further explained that in order to balance the pigtail of the fully integrated optical system 2 and the pigtail of the optical fiber loop 7 being on the same plane, while ensuring a reasonable connection between the left and right pins 20 of the fully integrated optical system 2 and the temperature control circuit, the relative heights among the three need to be fully considered and calculated. This may result in the soldering surface of the pin 20 of the fully integrated optical system 2 and the pad 12 of the temperature control circuit board 1 not being on the same plane. If the traditional soldering process for the pad 12 is used, the pad 12 and the pin 20 of the temperature control circuit board 1 will bear huge stress. At the same time, due to the existence of dimensional tolerances, this stress will be further aggravated. Under the action of external factors such as temperature, vibration, and shock, this stress will cause certain damage to the fiber optic gyroscope itself over time and even lead to its failure, seriously affecting the reliability and stability of the product. However, the method of inserting and spot-welding the connection hole 11 and the pin 20 after bending the flexible wire 10 provided in the embodiment of the present invention can effectively reduce and eliminate the above stress to ensure the reliability and stability of the product.

[0081] The fiber optic gyroscope provided in the embodiment of the present invention integrated with the fully integrated optical system 2 has higher requirements for heat dissipation due to its high integration and miniaturization. In terms of heat dissipation, the main heat-generating components of the fiber optic gyroscope provided in the embodiment of the present invention are concentrated in the fully integrated optical system 2, and the power consumption is approximately about 2W. The heat conduction and dissipation method of combining large-area bottom pasting and applying thermal grease on the heat-conducting surface is used to quickly and effectively transfer the heat to the aluminum alloy base 3. Relying on the excellent heat-conducting performance of the aluminum alloy, the heat is evenly dissipated and finally transferred to the main body or the surrounding environment installed therewith, avoiding device aging or failure caused by too high temperature and further increasing its own stability.

[0082] As a possible implementation, a heat insulation pad is provided between the inner wall of the optical fiber loop 7 and the shielding cavity 6, and the inner wall of the optical fiber loop 7 and the outer wall of the heat insulation pad, as well as the inner wall of the heat insulation pad and the inner wall of the shielding cavity 6, are glued together. And there is no need to glue a heat insulation pad between the outer wall of the optical fiber loop 7 to reduce the difference in the expansion coefficients between the inner and outer walls of the optical fiber loop 7, thereby reducing the adverse impact on the high and low temperature performance of the optical fiber loop 7.

[0083] In the second aspect, the embodiment of the present invention further provides an assembly method for a fiber optic gyroscope, including the following steps:

[0084] Provide a base 3, fixedly connect a control circuit board 4 to the bottom of the base 3, and fixedly connect a lower cover 5 to the bottom of the base 3 to seal the control circuit board 4; fix a temperature control circuit board 1 on the convex table surface at the top of the base 3; insert the connector of the temperature control circuit board 1 into the control circuit board 4 in an opposing manner; fix a fully integrated optical system 2 on the top of the convex table surface, insert the pin 20 into the flexible wire on the temperature control circuit board 1 and then spot weld them;

[0085] Provide a shielding cavity 6, fix an optical fiber loop 7 inside the cavity of the shielding cavity 6, and cover a shielding cover 9 on the top of the shielding cavity 6. The pigtail of the optical fiber loop 7 is led out from the wire outlet groove opened on the shielding cover 9;

[0086] Fasten and connect the shielding cavity 6 to the position on the base 3 that is outside the periphery of the fully integrated optical system 2;

[0087] Fuse the pigtail of the optical fiber loop 7 with the pigtail of the fully integrated optical system 2.

[0088] The present invention has greatly optimized the assembly process, improving from the traditional serial assembly process to a way where different components can be assembled in parallel, meeting the requirements of mass production. Each component module is both independent and cooperative with each other, and has great convenience and economy in subsequent maintenance.

[0089] Although the present invention has been described in connection with various embodiments herein, however, in the process of implementing the claimed invention, those skilled in the art can understand and achieve other variations of the disclosed embodiments by viewing the drawings, the disclosure content, and the like. In the specification, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude the case of multiple. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0090] Although the present invention has been described in connection with specific features and their embodiments, it is obvious that various modifications and combinations can be made to it without departing from the spirit and scope of the present invention. Accordingly, the present specification and the drawings are only exemplary descriptions of the present invention, and are considered to have covered any and all modifications, variations, combinations, or equivalents within the scope of the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A fiber optic gyroscope, characterized in that: The fiber optic gyroscope is a fiber optic gyroscope with a fully integrated optical system connected to a temperature-controlled circuit board; Fully integrated optical systems have multiple pins; The extension of the temperature control circuit board is provided with a flexible wire electrically connected thereto; the flexible wire is provided with connection holes, the number of the connection holes is equal to the number of the pins, the spacing between the connection holes is equal to the spacing between the pins, and the diameter of the connection holes is greater than the diameter of the pins; In the assembled state, the flexible wire is bent according to a matching bending radius, each pin is inserted into a connection hole corresponding to it in space, and then the pin and the flexible wire are welded together.

2. The fiber optic gyroscope according to claim 1, characterized in that A plurality of pads are arranged at intervals on the flexible wire, and the connection holes are opened on the pads. The connection holes are through holes that penetrate the flexible wire.

3. The fiber optic gyroscope according to claim 2, characterized in that The flexible conductor includes an insulating layer and a conductive wire. The insulating layer is made of at least TPC, PVC, PUR or silicone. The conductive wire is made of copper foil. The pad is made of gold immersion technology.

4. The fiber optic gyroscope according to claim 1, characterized in that The circumscribed circle diameter of the pin is d, and the diameter of the connecting hole is d+0.1mm~d+0.2mm.

5. The fiber optic gyroscope according to claim 2, characterized in that There are two flexible wires, which are symmetrically arranged on both sides of the temperature control circuit board; each flexible wire includes a connecting section and a welding section, and the welding pad is arranged in the welding section; One end of the connecting section is connected to the temperature control circuit board, and the other end of the connecting section is vertically and integrally connected to the welding section. There is a space between the inner side of the welding section and the temperature control circuit board to avoid interference.

6. The fiber optic gyroscope according to claim 1, characterized in that The fiber optic gyroscope also includes: a base, the bottom of the base is fixedly connected to the control circuit board, and the lower cover is fixedly connected to the bottom of the base to achieve sealing of the control circuit board; the temperature control circuit board is fixed to the convex surface on the top of the base, and the connector of the temperature control circuit board is plugged into the control circuit board; the fully integrated optical system is fixed to the top of the convex surface; The shielding cavity is fastened to the position of the base located at the periphery of the fully integrated optical system; the optical fiber ring is fixedly arranged in the cavity of the shielding cavity; the top of the shielding cavity is fastened to the shielding cover, and the shielding cover is provided with an outlet groove for leading out the pigtail of the optical fiber ring; the pigtail of the optical fiber ring is fused with the pigtail of the fully integrated optical system after being led out from the outlet groove; the upper cover is fixed on the shielding cover.

7. The fiber optic gyroscope according to claim 6, characterized in that The pigtail of the optical fiber ring and the pigtail of the fully integrated optical system are located in the same horizontal plane, or have a height difference, and the height difference is no more than 1 / 10 of the bending radius of the pigtail of the optical fiber ring.

8. The fiber optic gyroscope according to claim 6, characterized in that A plurality of heat-insulating pads are arranged at equal intervals between the optical fiber ring and the inner wall of the shielding cavity, and the inner wall of the optical fiber ring and the outer wall of the heat-insulating pad, as well as the inner wall of the heat-insulating pad and the inner wall of the shielding cavity are glued together.

9. The fiber optic gyroscope according to claim 6, characterized in that The side of the fully integrated optical system in contact with the boss surface is defined as a heat-conducting surface, and thermal grease is applied on the heat-conducting surface.

10. A method for assembling a fiber optic gyroscope, characterized in that: The steps include: Provide a base, fix the control circuit board at the bottom of the base, and fix the lower cover to the bottom of the base to seal the control circuit board; fix the temperature control circuit board on the convex surface at the top of the base; plug the connector of the temperature control circuit board into the control circuit board; after the fully integrated optical system is fixed on the top of the convex surface, plug the pins into the flexible wires on the temperature control circuit board and then spot weld them; A shielding cavity is provided, the optical fiber ring is fixed in the cavity of the shielding cavity, and a shielding cover is arranged on the top of the shielding cavity, and the pigtail of the optical fiber ring is led out from the outlet groove provided on the shielding cover; The shielding cavity is fastened to the base at a position outside the fully integrated optical system; Fusion splices the fiber pigtails of the fiber ring to the pigtails of the fully integrated optical system.

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