A pre-tensioning device

Abstract

The application provides a pre-tensioning device, which comprises a base plate, two clamping assemblies oppositely arranged on the base plate, and first and second fixing bases for assembling the two clamping assemblies on the base plate. Each clamping assembly comprises a shell with a receiving cavity, at least two clamping pieces arranged side by side in the shell, and a force applying rod fixed with one of the clamping pieces. The force applying rod is arranged to be movable along the axial direction of the force applying rod. The force applying rod of one of the clamping assemblies comprises a first extension extending to the outside of the first fixing base along the axial direction of the force applying rod. The first extension comprises a first tensioning piece. The first tensioning piece abuts against the outer surface of the first fixing base. The force applying rod of the other clamping assembly is fixed with the second fixing base. The two ends of the shell along the axial direction of the force applying rod are open. The clamping assembly further comprises a pressing piece on the shell for pressing and fixing the clamping pieces.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber Bragg grating. More particularly, it relates to a pre-tension device. BACKGROUND

[0002] Due to the advantages of distributed sensing, high precision, good long-term stability, anti-electromagnetic interference, being applicable to measurement under extreme conditions, and being capable of transmitting optical signals along a curved path, fiber Bragg grating has broad application prospects in the sensing field of large scientific devices. However, compared with traditional sensors, fiber Bragg grating sensors have a higher cost, and therefore a reliable operation mode is crucial.

[0003] Fiber Bragg grating is mainly sensitive to temperature and strain. In terms of measuring the amount of strain change, fiber Bragg grating can only perceive the influence of the axial stress field on the effective refractive index and period of the grating. As can be seen, the bending of the grating section will directly affect the measurement accuracy, and it is very important to keep the grating section of fiber Bragg grating in a straightened state. When fiber Bragg grating is used to measure in a low-temperature environment, it is necessary to provide a certain amount of pre-stress to ensure that the fiber Bragg grating measured in the low-temperature environment is also in a stretched state. SUMMARY

[0004] In view of the above problems, the present application provides a pre-tension device which keeps fiber Bragg grating in a straightened state during the experiment and provides pre-stress to fiber Bragg grating when needed.

[0005] To achieve the above object, the present application adopts the following technical solutions:

[0006] The present application provides a pre-tension device, comprising: a substrate; and

[0007] Two clamping assemblies are oppositely arranged on the substrate;

[0008] The two clamping assemblies are assembled on the substrate through a first fixed base and a second fixed base; the first fixed base comprises a first through hole; and the second fixed base comprises a second through hole;

[0009] The clamping assembly comprises a shell having a receiving cavity;

[0010] At least two clamping pieces are arranged side by side in the shell; and

[0011] A force applying rod is fixedly combined with one of the clamping pieces;

[0012] The force applying rod is configured to be movable in the axial direction of the force applying rod;

[0013] The force applying rods of the two clamping assemblies respectively pass through the first through hole and the second through hole;

[0014] The force applying rod of one of the clamping assemblies comprises a first extension part extending to the outside of the first fixed base along the axial direction of the force applying rod; the first extension part comprises a first tensioning part; the first tensioning part abuts against the outside surface of the first fixed base;

[0015] The force applying rod of the other clamping assembly is fixedly connected with the second fixed base;

[0016] The two ends of the shell along the axial direction of the force applying rod are open;

[0017] The clamping assembly further comprises a pressing part on the shell for pressing and fixing the clamping pieces; one end of the pressing part passes through the shell and corresponds to the clamping pieces, and the other end is exposed outside the shell.

[0018] In addition, preferably, the force applying rod connected with the second fixed base comprises a second extension part extending to the outside of the second fixed base along the axial direction of the force applying rod; the second extension part comprises a second tensioning part; the second tensioning part abuts against the outside surface of the second fixed base.

[0019] In addition, preferably, the end of the force applying rod connected with the second fixed base and away from the clamping pieces comprises a protruding ring structure; a spring is sleeved on the force applying rod connected with the second fixed base; one end of the spring abuts against the outside surface of the second fixed base, and the other end abuts against the protruding ring structure.

[0020] In addition, preferably, the first fixed base comprises a first groove recessed inward from the top wall surface thereof; in the axial direction of the force applying rod, the two ends of the first groove pass through the two opposite side wall surfaces of the first fixed base;

[0021] The second fixed base comprises a second groove recessed inward from the top wall surface thereof; in the axial direction of the force applying rod, the two ends of the second groove pass through the two opposite side wall surfaces of the second fixed base; the first groove and the second groove are coaxially arranged.

[0022] In addition, preferably, the material of the substrate and the clamping assembly is stainless steel.

[0023] In addition, preferably, the shell comprises a first screw hole and a fastening bolt arranged in the first screw hole; when the fastening bolt is tightened, the end of the fastening bolt located in the shell abuts against one of the clamping pieces and presses and fixes the clamping pieces; the fastening bolt forms the pressing part.

[0024] Further preferably, the housing includes a receiving groove formed by inwardly recessing the bottom wall thereof; the receiving groove extends through the surfaces of the two opposite side walls of the housing in the axial direction of the force applying rod; and the clamping pieces are located in the receiving groove.

[0025] Further preferably, the cross section of the receiving groove is rectangular.

[0026] Further preferably, the housing has an arched structure.

[0027] The present application has the following advantages:

[0028] The present application can realize clamping and fixing of the optical fiber through cooperation of the clamping pieces and the pressing members, and can realize pre-tensioning of the optical fiber through movement of the clamping pieces and the housing along the axial direction thereof driven by the force applying rod after the clamping pieces are pressed and fixed. BRIEF DESCRIPTION OF DRAWINGS

[0029] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0030] Figure 1 is a schematic diagram of the overall structure of the present application.

[0031] Figure 2 is a schematic diagram of the clamping assembly of the present application. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present application will now be described in detail below with reference to the accompanying drawings. Note that the relative arrangement, numerical expressions, and numerical values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0033] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application, its application, or uses.

[0034] Techniques and equipment known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0035] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Thus, other examples of the exemplary embodiments can have different values.

[0036] It should be noted that like numerals and letters refer to like items throughout the several views, where like items are discussed only once in detail to avoid obscuring the patent document, board and frame.

[0037] In order to keep the fiber Bragg grating in a straight state during the experiment, and to provide pre-stress for the fiber Bragg grating when needed in the experiment. The present application provides a pre-tension device, which is combined with Figure 1 、 Figure 2 As shown in the drawings, specifically, the pre-tension device comprises: a base plate 1; and two clamping assemblies 2 oppositely arranged on the base plate 1; the two clamping assemblies 2 are respectively assembled on the base plate 1 through a first fixed base 3 and a second fixed base 4; the first fixed base 3 comprises a first through hole; the second fixed base 4 comprises a second through hole; the clamping assembly 2 comprises a shell 5 with a receiving cavity, at least two clamping pieces 6 arranged side by side in the shell 5, and a force applying rod 7 fixedly combined with one of the clamping pieces 6; the force applying rod 7 is arranged to be movable in the axial direction of the force applying rod 7; the force applying rods 7 of the two clamping assemblies 2 respectively pass through the first through hole and the second through hole; the force applying rod 7 of one of the clamping assemblies 2 comprises a first extension 8 extending to the outside of the first fixed base in the axial direction of the force applying rod 7; the first extension 8 comprises a first tensioning piece 9; the first tensioning piece 9 abuts against the outer surface of the first fixed base 3; the force applying rod 7 of the other clamping assembly 2 is fixedly connected with the second fixed base 4; both ends of the shell 5 in the axial direction of the force applying rod 7 are open; the clamping assembly 2 further comprises a pressing piece on the shell 5 for pressing and fixing the clamping pieces 6; one end of the pressing piece passes through the shell 5 and corresponds to the clamping piece 6, and the other end is exposed outside the shell 5. The present application provides a pre-tension device which can be used for pre-tensioning of the fiber Bragg grating, the fiber Bragg grating is clamped by arranging at least two clamping pieces 6, and the force applying rod 7 drives the clamping pieces 6 clamping the fiber Bragg grating to move to adjust the force of the pre-tension device pre-tensioning the fiber Bragg grating by screwing the tensioning piece, which is suitable for pre-tensioning operation of different models of fiber Bragg gratings. The pre-tension device can keep the fiber Bragg grating in a straight state during the experiment, and can provide a certain pre-stress when needed in the experiment, and provides a reliable experimental operation platform, solving the problem of raw material waste caused by easy breaking of the fiber Bragg grating.

[0038] It can be understood that the tensioning member can be a nut screwed on the end of the force applying rod 7, and when the clamping piece 6 is pressed in the housing 5, the force applying rod 7 can drive the housing 5 to move along the axial direction of the force applying rod 7. The first fixed base 3 and the second fixed base 4 are oppositely arranged, and the two clamping assemblies 2 oppositely arranged on the substrate 1 form a group. Multiple groups of the above clamping assemblies 2 can be assembled on the substrate 1, and multiple optical fibers can be pre-tensioned to improve work efficiency and save working time. Specifically, five groups of clamping assemblies 2 can be arranged side by side on the substrate 1 through the fixed base.

[0039] The two clamping assemblies 2 arranged on the substrate 1 are used to determine the extension direction of the grating section of the fiber Bragg grating in the plane parallel to the plane where the substrate 1 is arranged. The first fixed base 3 and the second fixed base 4 are combined and fixed with the substrate 1 through bolts.

[0040] In a specific embodiment, the force applying rod connected with the second fixed base includes a second extension part extending to the outside of the second fixed base along the axial direction of the force applying rod. The second extension part includes a second tensioning member thereon, and the second tensioning member abuts against the outer surface of the second fixed base. In this embodiment, the two clamping assemblies 2 are connected and matched with the fixed base through the tensioning members, and the first tensioning member 9 and the second tensioning member can be adjusted to provide corresponding pre-tightening force for the fiber Bragg grating when needed. It can be understood that when the first tensioning member 9 and the second tensioning member are both nuts, threads are arranged on the first extension part 8 and the second extension part, and the outer diameter of the nut is greater than the hole diameter of the first through hole and the second through hole.

[0041] For the cooperation mode of the tensioning member and the force applying rod 7, the tensioning member can be a tension bolt, and a second threaded hole is formed in the extension of the force applying rod 7 in the axial direction of the force applying rod 7; a tension bolt is screwed in the second threaded hole; the tension bolt is located on the side of the fixed base away from the shell 5; a sleeve is sleeved on the extension of the force applying rod 7; one end of the sleeve is fixed with the fixed base, and the other end is in abutment with the head of the tension bolt; the sleeve serves as a support for the tension bolt and provides a force point for the tension bolt; when the tension bolt is screwed, the force applying rod 7 can move in the axial direction of the force applying rod 7. The tension bolt is located on the side of the fixed base away from the shell 5; the diameter of the head of the tension bolt is greater than the inner diameter of the sleeve. It can be understood that the second threaded hole serves to screw the tension bolt with the force applying rod 7. The tension bolt includes an internal hexagonal hole; the movement and positioning of the clamping assembly 2 can be achieved by screwing the tension bolt, the pre-tensioning of the optical fiber can be achieved, and when the clamping assembly 2 clamps the fiber Bragg grating, one of the two clamping assemblies 2 can be fixed, and the clamping assembly 2 can be moved by screwing the tension bolt on the other clamping assembly 2 to provide pre-tightening force for the optical fiber. The grating section of the fiber Bragg grating that needs to be pre-tensioned is placed between the two clamping assemblies 2, and the pre-tensioning of the fiber Bragg grating can be achieved by rotating the tension bolt.

[0042] In another specific embodiment, the end of the force applying rod 7 connected with the second fixed base 4 away from the clamping piece 6 includes a convex ring structure 13; a spring 14 is sleeved on the force applying rod 7 connected with the second fixed base 4; one end of the spring 14 is in abutment with the outer surface of the second fixed base 4, and the other end is in abutment with the convex ring structure 13. Through the above arrangement, the relaxation of the fiber Bragg grating and the clamping assembly 2 due to the mismatching of the expansion or shrinkage amount in thermal expansion and contraction can be prevented.

[0043] In a specific embodiment, the first fixed base 3 includes a first recess 15 formed by the inward recess of the top wall surface thereof; in the axial direction of the force applying rod 7, the two ends of the first recess 15 penetrate through the two opposite side wall surfaces of the first fixed base 3; the second fixed base 4 includes a second recess 16 formed by the inward recess of the top wall surface thereof; in the axial direction of the force applying rod 7, the two ends of the second recess 16 penetrate through the two opposite side wall surfaces of the second fixed base 4, and the first recess 15 and the second recess 16 are coaxially arranged. The function is to place the tail grating of the fiber Bragg grating and to reserve a channel for the fiber grating to pass through; the fiber grating can pass out from the two ends of the first fixed base 3 and the second fixed base 4 through the first recess 15 and the second recess 16, so that the fiber grating can be arranged parallel to the horizontal plane.

[0044] In a specific embodiment, the substrate 1 and the clamping assembly 2 are made of stainless steel. Stainless steel has good corrosion resistance. In addition to the chemical properties being stable, the physical properties of the substrate 1 and the clamping assembly 2 made of stainless steel are also very good, such as high temperature resistance and low temperature resistance, which can be applied to various complex working environments.

[0045] In order to fix the clamping pieces 6 and clamp the fiber grating, the housing 5 comprises a first threaded hole and a fastening bolt 17 arranged in the first threaded hole. When the fastening bolt 17 is tightened, the end of the fastening bolt 17 located in the housing 5 abuts against one of the clamping pieces 6 and presses the clamping pieces 6 tightly. The fastening bolt 17 forms the pressing member. Through the above arrangement, the fastening bolt 17 can stably fix the clamping pieces 6 in the housing 5, so that the fiber between the two clamping pieces 6 can be stably clamped.

[0046] In an optional embodiment, the housing 5 comprises a receiving groove formed by the inward recess of the bottom wall. In the axial direction of the force applying rod 7, the receiving groove penetrates through the surfaces of the two opposite side walls of the housing 5. The clamping pieces 6 are located in the receiving groove, and the receiving groove is used to accommodate the clamping pieces 6.

[0047] Specifically, the cross section of the receiving groove is rectangular. Its advantage is that since the cross section of the clamping piece 6 is rectangular, the receiving groove with a rectangular cross section can better cooperate with the clamping piece 6. After being pressed tightly, the contact area between the clamping piece 6 and the housing 5 is larger, the friction between them is increased, and the situation that the clamping piece 6 and the housing 5 are separated from each other after being pressed tightly is prevented, which affects the normal operation of the subsequent operation.

[0048] In addition, in an embodiment, the housing 5 has an arch-shaped structure. The bottom surface of the housing 5 is a plane, which can play a role in limiting rotation. The arch-shaped structure is more uniform in stress, so that the housing 5 is more stable. The arch-shaped housing 5 is convenient to assemble, and also saves the cost of raw materials. The housing 5 is used to initially fix the clamping pieces 6. The fastening bolt 17 is used to secondarily press and fix the clamping pieces 6, so as to prevent the fiber Bragg grating from sliding between the clamping pieces 6.

[0049] In a specific implementation process, the fiber Bragg grating to be pre-stretched is clamped between the two clamping pieces 6, the grating section of the fiber Bragg grating is arranged at the middle position of the pre-stretching device, i.e. between the two clamping assemblies 2, the adhesive tape is attached to the position where the fiber needs to be clamped by the clamping piece 6, the part of the fiber with the attached adhesive tape is arranged between the two clamping pieces 6, the fiber Bragg grating is horizontally arranged with two ends respectively extending from the first groove 15 and the second groove 16, the fastening bolt 17 is tightened to clamp the fiber Bragg grating by the clamping piece 6, the nut on one of the two clamping assemblies 2 is tightened to fix the position of the fiber Bragg grating, the nut on the other clamping assembly 2 is tightened to move the clamping assembly 2 outward, the pre-stretching of the fiber Bragg grating is realized, and the size of the pre-stretching force can be controlled through the reading of the demodulator connected to the fiber Bragg grating, and the greater the offset wavelength is, the greater the pre-stretching force is.

[0050] In summary, the clamping piece and the pressing piece are matched to clamp and fix the fiber, the clamping piece and the shell are driven by the force applying rod to move along the axial direction after the clamping piece is pressed and fixed, the fiber is pre-stretched, the pre-stretching device has simple structure, is convenient to operate, has strong compatibility, can be applied to the stretching of fibers with different diameters, the fiber Bragg grating can be kept in a straight state during the experiment, and the fiber Bragg grating is provided with pre-stress when needed in the experiment.

[0051] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and all the implementation modes cannot be exhausted here. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A pre-tensioning device, characterized in that, include: substrate; as well as Two clamping components are disposed opposite each other on the substrate; Two clamping components are respectively mounted on the substrate via a first fixing base and a second fixing base; the first fixing base includes a first through hole; the second fixing base includes a second through hole; The clamping assembly includes a housing with a receiving cavity; At least two clamping plates arranged side by side within the housing; as well as A force-applying rod that is fixed in conjunction with one of the clamping plates; The force-applying rod is configured to move along the axial direction of the force-applying rod; The force-applying rods of the two clamping components pass through the first through hole and the second through hole, respectively; One of the clamping components has a force-applying rod that includes a first extension extending along the axial direction of the force-applying rod to the outside of the first fixed base; the first extension includes a first tensioning member; the first tensioning member abuts against the outer surface of the first fixed base. The force-applying rod of another clamping component is connected and fixed to the second fixed base; The shell is open at both ends along the axial direction of the force-applying rod; The clamping assembly also includes a clamping member located on the housing for pressing and fixing the clamping pieces together; one end of the clamping member passes through the housing and corresponds to the clamping piece, and the other end is exposed outside the housing; The housing includes a first screw hole and a fastening bolt disposed in the first screw hole; the fastening bolt is configured such that when the fastening bolt is tightened, the end of the fastening bolt located inside the housing abuts against one of the clamping pieces and presses and fixes the clamping pieces together; the fastening bolt forms the clamping member.

2. The pre-tensioning device according to claim 1, characterized in that, The force-applying rod connected to the second fixed base includes a second extension extending along the axial direction of the force-applying rod to the outside of the second fixed base; the second extension includes a second tensioning member; the second tensioning member abuts against the outer surface of the second fixed base.

3. The pre-tensioning device according to claim 1, characterized in that, The end of the force-applying rod connected to the second fixed base away from the clamping piece includes a convex ring structure; a spring is fitted on the force-applying rod connected to the second fixed base; one end of the spring abuts against the outer surface of the second fixed base, and the other end abuts against the convex ring structure.

4. The pre-tensioning device according to claim 1, characterized in that, The first fixed base includes a first groove formed by the inward recess of its top wall surface; in the axial direction of the force-applying rod, the two ends of the first groove penetrate the two opposite side wall surfaces of the first fixed base. The second fixed base includes a second groove formed by the inward recess of its top wall surface; in the axial direction of the force-applying rod, the two ends of the second groove penetrate the two opposite side wall surfaces of the second fixed base, and the first groove and the second groove are coaxially arranged.

5. The pre-tensioning device according to claim 1, characterized in that, The substrate and the clamping assembly are both made of stainless steel.

6. The pre-tensioning device according to claim 1, characterized in that, The housing includes a receiving groove formed by an inward recess in its bottom wall; in the axial direction of the force-applying rod, the receiving groove extends through the two opposite sidewall surfaces of the housing; the clamping piece is located within the receiving groove.

7. The pre-tensioning device according to claim 6, characterized in that, The cross-section of the receiving groove is rectangular.

8. The pre-tensioning device according to claim 1, characterized in that, The shell has an arched structure.

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