Fiber grating sensor with heat insulation function

Abstract

The utility model discloses a fiber grating sensor with a heat insulation function, and relates to the technical field of fiber grating sensors, in particular to a fiber grating sensor with a heat insulation function, which comprises an armor optical cable, an outer shell and an elastic element, and a grating is engraved on the exposed part of the end part of the armor optical cable; the grating and one part of the elastic element are fixed together through the inner shell, multi-layer heat insulation protection is carried out on the inner shell through an aerogel felt layer, a ceramic silicone rubber layer and a polytetrafluoroethylene layer in the heat insulation assembly, external high temperature is prevented from being transmitted to the grating, and then the influence of the high temperature on the grating is avoided; the other end of the elastic element penetrates through the inner shell and the heat insulation assembly, and the other end of the elastic element is used for bearing force; the stress of the elastic element acts on the grating, the grating receives the stress change, and the wavelength of the grating shifts. According to the fiber grating sensor with the heat insulation function, the purpose of heat insulation is achieved, and meanwhile, the detection accuracy and sensitivity are not affected.

Description

Technical Field

[0001] The utility model relates to the technical field of optical fiber grating sensors, in particular to an optical fiber grating sensor with a heat insulation function. Background Art

[0002] Fiber Bragg grating is a diffraction grating formed by axially periodically modulating the refractive index of the optical fiber core through a certain method. It is a passive filter device. The displacement sensitive element of the fiber Bragg grating displacement sensor is a grating of a given reflection wavelength. The fiber Bragg grating is pre-stretched and encapsulated on the surface of the displacement elastic element with an adhesive so that the fiber Bragg grating is always kept in a tensioned state during the displacement change process. The two ends of the sensor are connected to a properly protected signal transmission armored optical cable. The sensitive element can convert the measured displacement into an electro-optical signal that can be read. The fiber Bragg grating displacement sensor is an optical sensor with great practical value. When the fiber Bragg grating displacement sensor is applied in some high-temperature scenarios, the high temperature causes stress changes in the sensitive elements and gratings in the fiber Bragg grating displacement sensor, resulting in inaccurate related data. In severe cases, the grating is damaged by the high temperature.

[0003] In the published Chinese patent application, publication number: CM219935009U, patent name: A fiber Bragg grating sensor with heat insulation function, although the prior art can protect the fiber Bragg grating sensor from being damaged by high temperature during hot casting of anchors by setting the first fireproof layer and the second fireproof layer. However, the prior art wraps the grating layer by layer, which reduces the sensitivity of the grating when receiving stress changes, thereby reducing the accuracy and sensitivity of the entire fiber Bragg grating detection.

[0004] In summary, in order to solve the problems existing in the prior art, this application is specially proposed to solve them. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the utility model provides a fiber grating sensor with a heat insulation function, which solves the problems raised in the above background technology.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the utility model is implemented through the following technical solutions: a fiber grating sensor with heat insulation function, comprising an armored optical cable, an outer shell and an elastic element, a grating is engraved on the exposed part of the end of the armored optical cable, the grating is arranged inside the outer shell, the elastic element is installed inside the outer shell, and most of one end of the elastic element is in contact with the grating; an inner shell is arranged inside the outer shell, the armored optical cable passes through the inner shell, and the grating is located inside the inner shell, most of one end of the elastic element is located inside the inner shell, and most of the grating and one end of the elastic element are fixed in the inner shell by adhesive potting; a heat insulation component is arranged outside the inner shell, and the heat insulation component is composed of an aerogel felt layer, a ceramic silicone rubber layer, and a polytetrafluoroethylene layer; the other end of the elastic element passes through the inner shell and the heat insulation component in sequence.

[0009] Optionally, plugs are fixedly installed at both ends of the outer shell, a pull rod outer shell is fixedly installed on one of the plugs, a displacement rod is slidably arranged in the pull rod outer shell, one end of the displacement rod is fixedly connected to a spring, and the end of the spring away from the displacement rod is fixedly connected to the elastic element.

[0010] Optionally, a stabilizing piece is installed on the plug, and the armored optical cable passes through the stabilizing piece and the plug in sequence.

[0011] Optionally, the stabilizing member is composed of a stop shell and a tail sleeve, the end of the stop shell away from the plug is in the shape of a multi-petal cylinder, the inner wall of the stop shell is engraved with teeth, and the tail sleeve is sleeved on the end of the stop shell away from the plug.

[0012] Optionally, a layer of graphite film wrapping the inner shell is disposed on the outside.

[0013] Optionally, the elastic element is in a cantilever beam structure as a whole, the elastic element is made of a metal sheet, and a plurality of vacuum cavities are arranged inside the elastic element.

[0014] (III) Beneficial effects

[0015] The utility model provides a fiber grating sensor with heat insulation function, which has the following beneficial effects:

[0016] The fiber grating sensor with heat insulation function has a heat insulation effect through the coordinated arrangement of the grating, elastic element, inner shell and heat insulation component. The grating and a part of the elastic element are fixed together through the inner shell. The inner shell is provided with multi-layer heat insulation protection through the aerogel felt layer, ceramic silicone rubber layer and polytetrafluoroethylene layer in the heat insulation component to prevent the external high temperature from being transmitted to the grating, thereby avoiding the influence of high temperature on the grating. The other end of the elastic element is passed through the inner shell and the heat insulation component, and the other end of the elastic element is subjected to force; the stress of the elastic element acts on the grating, the grating receives the stress change, and its wavelength is shifted. While achieving the purpose of heat insulation, the detection accuracy and sensitivity of the fiber grating sensor with heat insulation function are not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 This is a three-dimensional structural schematic diagram of a fiber grating sensor with heat insulation function according to the utility model;

[0019] Figure 2 This is a front view structural schematic diagram of a fiber grating sensor with heat insulation function according to the utility model;

[0020] Figure 3 This is a schematic cross-sectional view of a fiber grating sensor with heat insulation function according to the utility model;

[0021] Figure 4 for Figure 3 The enlarged structural diagram at A in the middle;

[0022] Figure 5 for Figure 3 The enlarged structural diagram at B in the middle;

[0023] Figure 6 for Figure 3 Enlarged structural diagram at point C in the middle.

[0024] In the figure: 1, outer shell; 2, pull rod shell; 3, armored optical cable; 4, stabilizing member; 401, stop shell; 402, tail sleeve; 5, plug; 6, grating; 7, elastic element; 8, spring; 9, displacement pull rod; 10, inner shell; 11, aerogel felt layer; 12, ceramic silicone rubber layer; 13, polytetrafluoroethylene layer. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that 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 present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indications or implications.

[0026] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0027] See also Figures 1 to 6 The utility model provides a technical solution: a fiber grating sensor with heat insulation function, including an armored optical cable 3, an outer shell 1 and an elastic element 7, a grating 6 is engraved on the exposed end portion of the armored optical cable 3, the grating 6 is arranged inside the outer shell 1, and the elastic element 7 is installed inside the outer shell 1, and most of one end of the elastic element 7 is in contact with the grating 6.

[0028] An inner shell 10 is arranged inside the outer shell 1, the armored optical cable 3 passes through the inner shell 10, and the grating 6 is located inside the inner shell 10, one end of the elastic element 7 is mostly located inside the inner shell 10, and the grating 6 and one end of the elastic element 7 are mostly fixed in the inner shell 10 by adhesive potting.

[0029] The inner shell 10 is provided with a heat insulation component on its outside, which is composed of an aerogel felt layer 11, a ceramic silicone rubber layer 12, and a polytetrafluoroethylene layer 13. The other end of the elastic element 7 passes through the inner shell 10 and the heat insulation component in sequence. The heat insulation component is used to perform multi-layer heat insulation on the inner shell 10 to prevent the external high temperature from being transmitted to the grating 6.

[0030] Among them, the grating 6 and one end of the elastic element 7 are mostly fixed together through the inner shell 10, and the inner shell 10 is provided with multi-layer thermal insulation protection through the aerogel felt layer 11, the ceramic silicone rubber layer 12, and the polytetrafluoroethylene layer 13 in the thermal insulation component to prevent the external high temperature from being transmitted to the grating 6, thereby avoiding the influence of the high temperature on the grating 6, and the other end of the elastic element 7 is passed through the inner shell 10 and the thermal insulation component in sequence, and the other end of the elastic element 7 is subjected to force. The stress of the elastic element 7 acts on the grating 6, the grating 6 receives the stress change, and the wavelength of the grating 6 is shifted, thereby achieving the purpose of detecting the displacement. This fiber grating sensor with thermal insulation function achieves the purpose of thermal insulation while its detection accuracy and sensitivity are not affected.

[0031] Specifically, plugs 5 are fixedly installed at both ends of the outer shell 1, a pull rod outer shell 2 is fixedly installed on one plug 5, a displacement rod 9 is slidably arranged in the pull rod outer shell 2, one end of the displacement rod 9 is fixedly connected to a spring 8, and the end of the spring 8 away from the displacement rod 9 is fixedly connected to the elastic element 7.

[0032] The plug 5 is used to seal the end of the outer shell 1. The displacement rod 9 is used to detect the displacement. The displacement rod 9 is slightly displaced relative to the outer shell 1 after being subjected to external force. The spring 8 converts the slightly displaced displacement of the displacement rod 9 into stress, which in turn acts on the grating 6 through the elastic element 7. The grating 6 receives the change of stress, and the wavelength of the grating 6 is shifted due to the influence of stress, thereby realizing the detection of the displacement.

[0033] More specifically, a stabilizing member 4 is installed on the plug 5, and the armored optical cable 3 passes through the stabilizing member 4 and the plug 5 in sequence. The stabilizing member 4 is composed of a stopper housing 401 and a tail sleeve 402. The end of the stopper housing 401 away from the plug 5 is in a multi-petal cylindrical shape, and the inner side wall of the stopper housing 401 is engraved with tooth patterns. The tail sleeve 402 is sleeved on the end of the stopper housing 401 away from the plug 5. The tail sleeve 402 is threadedly connected to the stopper housing 401.

[0034] Among them, the stabilizing member 4 is used to fix the armored optical cable 3 and the plug 5, and strengthen the connection strength between the two. After the armored optical cable 3 passes through the tail sleeve 402, the stop shell 401, and the plug 5 in sequence, the teeth on the inner wall of the stop shell 401 clamp the armored optical cable 3, and by twisting the tail sleeve 402 onto the stop shell 401, the tail sleeve 402 is rotated and tightly sleeved on the stop shell 401, so that each multi-petal support of the stop shell 401 is tightly buckled with the armored optical cable 3, thereby fixing the armored optical cable 3 and improving the tensile strength between the armored optical cable 3 and the outer shell 1.

[0035] Specifically, a layer of graphite film is disposed on the outside of the inner shell 10 to wrap the inner shell 10 .

[0036] The graphite film is used to thermally insulate the inner shell 10 .

[0037] Specifically, the elastic element 7 is a cantilever beam structure as a whole, the elastic element 7 is made of a metal sheet, and a plurality of vacuum cavities are arranged inside the elastic element 7 .

[0038] Among them, by arranging a vacuum cavity inside the elastic element 7 and using the vacuum cavity layer to achieve heat insulation, the heat conduction of the elastic element 7 itself is greatly reduced, so that the elastic element 7 also achieves the purpose of heat insulation.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fiber Bragg grating sensor with heat insulation function, characterized in that: The invention comprises an armored optical cable (3), an outer shell (1) and an elastic element (7), wherein a grating (6) is engraved on the exposed end portion of the armored optical cable (3), the grating (6) is arranged inside the outer shell (1), the elastic element (7) is installed inside the outer shell (1), and one end of the elastic element (7) is mostly in contact with the grating (6); An inner shell (10) is arranged inside the outer shell (1), the armored optical cable (3) passes through the inner shell (10), and the grating (6) is located inside the inner shell (10), one end of the elastic element (7) is mostly located inside the inner shell (10), and one end of the grating (6) and the elastic element (7) are mostly fixed in the inner shell (10) by potting with an adhesive; A heat insulation component is arranged outside the inner shell (10), and the heat insulation component is composed of an aerogel felt layer (11), a ceramic silicone rubber layer (12), and a polytetrafluoroethylene layer (13); the other end of the elastic element (7) passes through the inner shell (10) and the heat insulation component in sequence.

2. The fiber Bragg grating sensor with heat insulation function according to claim 1, characterized in that: Both ends of the outer shell (1) are fixedly mounted with plugs (5), a pull rod outer shell (2) is fixedly mounted on one of the plugs (5), a displacement pull rod (9) is slidably arranged inside the pull rod outer shell (2), one end of the displacement pull rod (9) is fixedly connected to a spring (8), and the end of the spring (8) away from the displacement pull rod (9) is fixedly connected to an elastic element (7).

3. The fiber Bragg grating sensor with heat insulation function according to claim 2, characterized in that: A stabilizing member (4) is installed on the plug (5), and the armored optical cable (3) passes through the stabilizing member (4) and the plug (5) in sequence.

4. The fiber Bragg grating sensor with heat insulation function according to claim 3, characterized in that: The stabilizing member (4) is composed of a stop shell (401) and a tail sleeve (402); the end of the stop shell (401) away from the plug (5) is in the shape of a multi-petal cylinder; the inner wall of the stop shell (401) is engraved with tooth patterns; and the tail sleeve (402) is sleeved on the end of the stop shell (401) away from the plug (5).

5. The fiber Bragg grating sensor with heat insulation function according to claim 1, characterized in that: The inner shell (10) is provided with a layer of graphite film wrapping the inner shell (10) on its outside.

6. The fiber Bragg grating sensor with heat insulation function according to claim 1, characterized in that: The elastic element (7) is in the form of a cantilever beam structure as a whole; the elastic element (7) is made of a metal sheet; and a plurality of vacuum cavities are arranged inside the elastic element (7).

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