Heat preservation type optical fiber ring shielding cover

Abstract

The utility model relates to a heat preservation type optical fiber ring shielding case, which comprises an upper shielding case with an annular structure and a lower shielding case with an annular structure, the upper shielding case is arranged on the lower shielding case, an accommodating space for accommodating an optical fiber ring is arranged between the upper shielding case and the lower shielding case, and vacuum chambers are arranged in the upper shielding case and the lower shielding case. The heat preservation type optical fiber ring shielding case provided by the utility model is composed of the upper shielding case and the lower shielding case which are of vacuum structures, and the vacuum is utilized to play a role in heat insulation and heat preservation, so that the working efficiency of an optical fiber ring can be effectively improved; and the shielding cover is compact in structure and vacuum inside, so that the requirements of low weight and low volume of the gyroscope in the market are met.

Description

TECHNICAL FIELD

[0001] The utility model belongs to optical fiber gyroscope technical field, especially relates to a heat preservation type optical fiber ring shield case. BACKGROUND

[0002] The iron nickel soft magnetic alloy shield case is the protective cover of the optical fiber ring as the core component of the optical fiber gyroscope, which is essential for the heat preservation while playing the magnetic shielding effect. The zero bias related error of the optical fiber gyroscope can be divided into the error caused by internal factors and the error caused by external factors, and the error caused by external factors mainly includes the Shup error caused by temperature, the photoelastic effect caused by temperature, the modulation error caused by temperature, the bias point drift error caused by temperature and the like. The Shup error caused by temperature mainly comes from the thermal asymmetry of the optical fiber ring, so the heat preservation treatment is carried out to the optical fiber ring, which can effectively reduce the influence of temperature on the precision of the gyroscope. At the same time, the optical fiber ring includes the fiber core, the coating layer, the cladding and the optical fiber glue. The thermal expansion coefficients of different materials are also different. The stress change caused by the temperature change causes the change of the refractive index of the optical fiber, and influences the stability of the precision of the optical fiber gyroscope. In order to reduce the influence of temperature on the optical fiber ring, researchers try to use the four-level symmetrical winding method, the eight-level symmetrical winding method or even the sixteen-level symmetrical winding method to improve the symmetry of the optical fiber ring and reduce the Shup error and the photoelastic effect caused by temperature, but this method cannot fundamentally solve the influence of temperature on the optical fiber ring. CONTENT

[0003] Therefore, the utility model aims at the shortage of prior art, provides a heat preservation type optical fiber ring shield case, reduces the speed of the external temperature conduction to the optical fiber ring.

[0004] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0005] A heat preservation type optical fiber ring shield case, including the annular structure of upper shield case and the annular structure of lower shield case, upper shield case sets up on lower shield case, and the accommodating space of accommodating optical fiber ring is arranged between upper shield case and lower shield case, and vacuum chamber is arranged in the inside of upper shield case and lower shield case.

[0006] In order to better realize the utility model, further optimization is made in the above structure, and the lower shield case is of U-shaped structure, and the upper shield case is covered and arranged on the top of the lower shield case.

[0007] In order to better realize the utility model, further optimization is made in the above structure, and the upper shield case is of annular flat plate structure.

[0008] In order to better realize the utility model, further optimization is made in the above structure, and the thickness of the two side walls of the vacuum chamber is 0.6mm.

[0009] In order to better realize the utility model, the thickness of the vacuum chamber is 1mm in the above structure.

[0010] In order to better realize the utility model, the upper shielding cover and the lower shielding cover are made of iron-nickel soft magnetic alloy material in the above structure.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] The heat preservation type optical fiber ring shielding cover is composed of the vacuum structure upper shielding cover and the lower shielding cover, utilizes vacuum to play the heat insulation and preservation role, can effectively improve the working efficiency of the optical fiber ring, the shielding cover structure is compact, the inside is vacuum, satisfies the low weight and low volume requirement of the gyroscope on the market, the shielding cover made of iron-nickel soft magnetic alloy material has the magnetic shielding effect, and the electromagnetic interference can be effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0014] Figure 1 It is the structure schematic view of the heat preservation type optical fiber ring shielding cover of the utility model.

[0015] In the drawing:

[0016] 1-upper shielding cover, 2-lower shielding cover, 3-accommodating space, 4-vacuum chamber, 11-optical fiber ring. CONCRETE IMPLEMENTING METHOD

[0017] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme of the utility model will be described in detail below. Obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other implementation manners obtained by those skilled in the art without creative labor belong to the range protected by the utility model.

[0018] In the description of the utility model, it needs to explain, unless otherwise stated, the meaning of "a plurality of" is two or more than two;The terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and is not indicative or suggestive of the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" and the like are only for descriptive purposes and cannot be understood as indicative or suggestive of relative importance.

[0019] In the description of the utility model, it also needs to explain that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected;It can be mechanical connection, or electrical connection;It can be directly connected, or indirectly connected through an intermediate medium. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0020] The utility model provides a heat preservation type optical fiber ring shield case, including the upper shield case 1 of annular structure and the lower shield case 2 of annular structure, the upper shield case 1 and the lower shield case 2 all adopt iron nickel soft magnetic alloy material, have magnetic shielding effect, can effectively reduce electromagnetic interference. The upper shield case 1 is set on the lower shield case 2, in this embodiment, the lower shield case 2 is U type structure, and the upper shield case 1 is annular flat plate structure, and the upper shield case 1 is covered and set on the top of the lower shield case 2.

[0021] The upper shield case 1 and the lower shield case 2 of U type structure form the containing space 3 containing the optical fiber ring 11 between, the optical fiber ring 11 is set in the containing space 3, and the optical fiber ring exit hole can be determined according to actual assembly. The upper shield case 1 and the lower shield case 2 are all provided with vacuum chamber 4 in its inside.

[0022] In practical application, due to the bias of heat source, the thermal conductivity of optical fiber ring axial and radial is different, finally causes the temperature change rate of each point of optical fiber ring to be different, and Shup effect always exists. The greater the distance between the optical fiber temperature change point and the midpoint of the optical fiber, the greater the non-reciprocity error of the optical fiber gyroscope caused by Shup effect.

[0023] The refractive index caused by the transverse orthogonal stress of the optical fiber is (1)

[0024]

[0025] In the formula, E is Young's modulus, n is the refractive index of the optical fiber core, v is Poisson's ratio, p 11 , p12 is the photoelastic tensor; p v , p h are the stresses in the two orthogonal transverse directions of the fiber, respectively.

[0026] The linear birefringence of the fiber under the two orthogonal transverse stresses can thus be calculated as follows: (2)

[0027]

[0028] λ is the wavelength of the light. (2) is the linear birefringence of the fiber under the two orthogonal transverse stresses. The linear birefringence is proportional to the difference between the transverse stresses. For a fiber wound into a ring, the difference refers to the difference between the stress along the sensitive axis of the fiber ring (axial stress) and the stress along the radius of the fiber ring (radial stress).

[0029] The size of the shielding cover of the present application and the conventional shielding cover is as follows:

[0030] The thickness of the two side walls of the vacuum chamber 4 of the present application is 0.6 mm, and the thickness of the vacuum chamber 4 is 1 mm. The thickness of the non-vacuum shielding cover is 1.2 mm. The shielding cover designed in the present application is compact in structure and has a vacuum inside, thus meeting the requirements of low weight and low volume of gyroscopes on the market.

[0031] Moreover, according to the modeling based on the above-mentioned size and the attachment of the fiber ring, finite element analysis using Ansys software shows that, after the outer surface of the shielding cover is set to 80℃ for 200s, the maximum temperature of the fiber ring is 55℃, and the minimum temperature is 24.5℃. According to the modeling of the non-vacuum shielding cover based on the above-mentioned size, the same shielding cover temperature and time are set, and the maximum temperature of the fiber ring reaches 80℃, and the minimum temperature is 26.3℃. According to the simulation results, the heat insulation performance of the vacuum shielding cover is more obvious than that of the non-vacuum shielding cover, and at the same time, the vacuum shielding cover has a lighter weight due to the vacuum inside.

[0032] The present application realizes excellent magnetic shielding effect and heat preservation performance through unique vacuum design and the high magnetic shielding performance of nickel-iron soft magnetic alloy, and has wide application prospect.

[0033] The above merely illustrates the specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A thermal-type optical fiber loop shield, characterized by: The upper shielding cover (1) comprising a ring structure and the lower shielding cover (2) comprising a ring structure, the upper shielding cover (1) is arranged on the lower shielding cover (2), a containing space (3) containing an optical fiber ring (11) is arranged between the upper shielding cover (1) and the lower shielding cover (2), and the upper shielding cover (1) and the lower shielding cover (2) are internally provided with vacuum chambers (4).

2. A thermal optical fiber loop shield according to claim 1, wherein: The lower shielding cover (2) is in a U-shaped structure, and the upper shielding cover (1) covers the top of the lower shielding cover (2).

3. A shield for a temperature-regulated fiber optic loop according to claim 2, wherein: The upper shielding cover (1) is in a flat plate structure of a ring shape.

4. A thermal optical fiber loop shield according to claim 3, wherein: The thickness of the two side walls of the vacuum chamber (4) is 0.6 mm.

5. A thermal optical fiber loop shield according to claim 4, wherein: The thickness of the vacuum chamber (4) is 1 mm.

6. A thermal shield for an optical fiber cable according to any one of claims 1-5, characterized in that: The upper shielding cover (1) and the lower shielding cover (2) are made of iron-nickel soft magnetic alloy material.

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