Fiber-optic gyroscope magnetic shielding structure based on additive manufacturing

Abstract

The invention provides a fiber-optic gyroscope magnetic shielding structure based on additive manufacturing. The fiber-optic gyroscope magnetic shielding structure sequentially comprises an outer shielding layer, a first insulating layer, a middle transition layer, a second insulating layer, an inner high-permeability layer and a circuit board supporting structure from outside to inside, the outer shielding layer, the first insulating layer, the middle transition layer, the second insulating layer and the inner high-permeability layer are respectively divided into an upper part and a lower part, and the upper part and the lower part are integrally formed through additive manufacturing and then are mechanically connected; the outer shielding layer is obtained by additive manufacturing of a high-saturation permeability material, and the outer surface of the outer shielding layer is provided with a bionic honeycomb or fractal magnetic flux guide groove; the middle transition layer is obtained by additive manufacturing of a porous metal material; and the inner high-magnetic-conductivity layer is obtained by additive manufacturing of a nanocrystalline soft magnetic alloy or permalloy material. The technical problems that an existing magnetic shielding structure of the fiber-optic gyroscope is large in machining difficulty, low in shielding efficiency, high in weight and difficult to integrate can be solved.

Description

Technical Field

[0001] This invention relates to the field of inertial navigation and precision instrument technology, and in particular to a magnetic shielding structure for fiber optic gyroscopes based on additive manufacturing. Background Technology

[0002] Fiber optic gyroscopes, as high-precision angular velocity sensors, are widely used in aerospace, autonomous driving, precision guidance, and other fields. Their working principle is based on the Sagnac effect, making them extremely sensitive to external magnetic fields. In particular, the Earth's magnetic field or electromagnetic interference from equipment can cause non-reciprocal phase differences, leading to zero-bias drift and severely affecting measurement accuracy.

[0003] Traditional magnetic shielding structures have the following problems: traditional stamping and welding processes are difficult to achieve complex curved surfaces and irregular shapes, which limits the optimization of shielding efficiency; multi-layer shielding requires separate processing and assembly, which can easily introduce gaps and magnetic leakage; the metal shielding layer is relatively thick and heavy, which is not conducive to the lightweighting of the system; permalloy is difficult to process and has low material utilization. Summary of the Invention

[0004] This invention provides a magnetic shielding structure for fiber optic gyroscopes based on additive manufacturing, which can solve the technical problems of existing magnetic shielding structures for fiber optic gyroscopes, such as high processing difficulty, low shielding efficiency, high weight, and difficulty in integration.

[0005] This invention provides a magnetic shielding structure for a fiber optic gyroscope based on additive manufacturing, comprising, from the outside to the inside, an outer shielding layer, a first insulating layer, an intermediate transition layer, a second insulating layer, an inner high-permeability layer, and a circuit board support structure. Each of the outer shielding layer, the first insulating layer, the intermediate transition layer, the second insulating layer, and the inner high-permeability layer is divided into upper and lower parts, which are integrally formed by additive manufacturing and then mechanically connected. The outer shielding layer is obtained by additive manufacturing using a high-saturation permeability material, and its outer surface is provided with biomimetic honeycomb or fractal magnetic flux guiding grooves. The intermediate transition layer is obtained by additive manufacturing using a porous metal material. The inner high-permeability layer is obtained by additive manufacturing using a nanocrystalline soft magnetic alloy or permalloy material.

[0006] Preferably, the additive manufacturing process is selective laser melting, with a layer thickness of 20-50 μm and a forming accuracy of ±0.1 mm.

[0007] Preferably, both the first insulating layer and the second insulating layer are ceramic insulating layers with a thickness on the order of micrometers.

[0008] Preferably, the inner high magnetic permeability layer and the circuit board support structure are subjected to vacuum heat treatment after forming.

[0009] Preferably, the temperature range of the vacuum heat treatment is 800–1100°C, and the holding time ranges from 2 to 4 hours.

[0010] The technical solution of this invention enables the integrated forming of complex multi-layer structures through additive manufacturing, avoiding assembly gaps and improving the continuity of magnetic shielding; the gradient material design takes into account both strong and weak field shielding, improving shielding effectiveness by more than 30%; the biomimetic structure guides magnetic flux and reduces local magnetic saturation; the lightweight design (weight reduction of 20-40%) is suitable for weight-sensitive scenarios such as aerospace; it can be conformally designed with fiber optic loops, improving space utilization and system integration. Attached Figure Description

[0011] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0012] Figure 1 A schematic diagram of a magnetic shielding structure for an additively manufactured fiber optic gyroscope is shown, according to an embodiment of the present invention.

[0013] The above figures include the following reference numerals:

[0014] 1. Outer shielding layer; 2. First insulating layer; 3. Intermediate transition layer; 4. Second insulating layer; 5. Inner high permeability layer; 6. Circuit board support structure. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0018] like Figure 1 As shown, this invention provides a fiber optic gyroscope magnetic shielding structure based on additive manufacturing, comprising, from the outside to the inside, an outer shielding layer, a first insulating layer, an intermediate transition layer, a second insulating layer, an inner high-permeability layer, and a circuit board support structure. The outer shielding layer, the first insulating layer, the intermediate transition layer, the second insulating layer, and the inner high-permeability layer are each divided into upper and lower parts, which are integrally formed by additive manufacturing and then mechanically connected. The outer shielding layer is obtained by additive manufacturing using a high-saturation permeability material, and its outer surface is provided with biomimetic honeycomb or fractal magnetic flux guiding grooves. The intermediate transition layer is obtained by additive manufacturing using a porous metal material. The inner high-permeability layer is obtained by additive manufacturing using a nanocrystalline soft magnetic alloy or permalloy material.

[0019] In this embodiment, the outer shielding layer, made of a high-saturation permeability alloy, attenuates strong magnetic fields. The biomimetic honeycomb or fractal flux guiding grooves on the outer surface of the outer shielding layer guide magnetic field lines to circumvent, reducing flux penetration. The intermediate transition layer, made of porous metal, serves for vibration damping and flux guidance. The inner high-permeability layer, also made of a high-permeability alloy, shields weak magnetic fields and the Earth's magnetic field. The interior of the inner high-permeability layer contains a conformal cavity to accommodate fiber optic loops and circuit modules. The lower cavity of the circuit board support structure is used to place optical components, while the upper cavity is used to place the circuit board. Both the first and second insulating layers are micrometer-thick ceramic insulating layers, serving to mitigate magnetic flux and dampen vibrations. This shielding structure is integrally formed using additive manufacturing.

[0020] Among them, a strong magnetic field refers to a magnetic field with a magnetic field strength greater than 1T, and a weak magnetic field refers to a magnetic field with a magnetic field strength less than 100μT.

[0021] According to one embodiment of the present invention, the additive manufacturing process is selective laser melting, with a layer thickness of 20-50 μm and a forming accuracy of ±0.1 mm.

[0022] According to one embodiment of the present invention, in order to eliminate residual stress and improve magnetic permeability, the inner high-permeability layer and the circuit board support structure are subjected to vacuum heat treatment after forming. Specifically, the temperature range of the vacuum heat treatment is 800–1100°C, and the holding time ranges from 2 to 4 hours.

[0023] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figure 1 The present invention provides a detailed description of the additive manufacturing-based magnetic shielding structure for fiber optic gyroscopes.

[0024] like Figure 1 As shown, the outer shielding layer is made of Fe-49Co-2V alloy powder, formed by laser selective melting process, with a thickness of 1.5mm, and is used to shield against strong external electromagnetic interference.

[0025] Intermediate transition layer: It adopts a gradient pore design (porosity 10%–30%), is made of Fe-Si alloy, and has a thickness of 1.0 mm. It has both shock absorption and magnetic flux release functions.

[0026] Inner high permeability layer: made of Ni 80 Fe 20 Permalloy powder was formed to a thickness of 0.8 mm and then vacuum annealed at 1000℃, which increased the magnetic permeability to μr>50000.

[0027] The circuit board support structure and the inner high magnetic permeability layer 5 use the same materials and processing methods.

[0028] A 5μm thick Al2O3 insulating layer (2, 4) is deposited between each layer using a plasma spraying process to prevent eddy currents;

[0029] The overall structure is printed in one piece using a laser selective melting device, using metal powder with a particle size of 15-45μm, a laser power of 300W, and a scanning speed of 1200mm / s.

[0030] In summary, this invention provides a magnetic shielding structure for fiber optic gyroscopes based on additive manufacturing. Additive manufacturing enables the integrated forming of complex multi-layered structures, avoiding assembly gaps and improving the continuity of magnetic shielding. The gradient material design balances strong and weak field shielding, improving shielding effectiveness by over 30%. The biomimetic structure guides magnetic flux, reducing local magnetic saturation. The lightweight design (20-40% weight reduction) is suitable for weight-sensitive applications such as aerospace. It can be conformally designed with fiber optic loops, improving space utilization and system integration.

[0031] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A magnetic shielding structure for a fiber optic gyroscope based on additive manufacturing, characterized in that, From the outside in, it includes an outer shielding layer, a first insulating layer, an intermediate transition layer, a second insulating layer, an inner high-permeability layer, and a circuit board support structure. Each of the outer shielding layer, the first insulating layer, the intermediate transition layer, the second insulating layer, and the inner high-permeability layer is divided into upper and lower parts, which are integrally formed through additive manufacturing and then mechanically connected. The outer shielding layer is obtained through additive manufacturing using a high-saturation permeability material, and its outer surface is provided with biomimetic honeycomb or fractal magnetic flux guiding grooves. The intermediate transition layer is obtained through additive manufacturing using a porous metal material. The inner high-permeability layer is obtained through additive manufacturing using nanocrystalline soft magnetic alloy or permalloy material.

2. The structure according to claim 1, characterized in that, The additive manufacturing process is selective laser melting, with a layer thickness of 20–50 μm and a forming accuracy of ±0.1 mm.

3. The structure according to claim 1, characterized in that, Both the first insulating layer and the second insulating layer are ceramic insulating layers with a thickness on the order of micrometers.

4. The structure according to claim 1, characterized in that, The inner high magnetic permeability layer and the circuit board support structure are subjected to vacuum heat treatment after forming.

5. The structure according to claim 4, characterized in that, The temperature range of the vacuum heat treatment is 800–1100℃, and the holding time ranges from 2 to 4 hours.

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