Fiber bragg grating displacement meter with adjustable pre-stretching function

Abstract

The utility model discloses a fiber bragg grating displacement meter with an adjustable pre-stretching function, which comprises a mounting box, a fiber bragg grating displacement sensor and a tension sensor are arranged in the mounting box in a sliding manner, and the fiber bragg grating displacement sensor and the tension sensor are connected through a connecting rod. The side, away from the fiber grating displacement sensor, of the tension sensor is rotationally connected with one end of an adjusting rod, the other end of the adjusting rod extends out of the mounting box and is fixedly connected with a knob, the circumferential side wall of the adjusting rod is in threaded connection with the corresponding side wall of the mounting box, and a locking device is arranged on the mounting box. The locking device is used for locking the fiber grating displacement sensor; the display is arranged on the upper surface of the mounting box, the connecting lugs are arranged at the four corners of the mounting box, the displacement meter can convert pre-stretching of the fiber grating displacement sensor into a tension value of the tension sensor, and the tension value is displayed on the display, so that an operator can intuitively feel the change of the pre-stretching amount of the fiber grating displacement sensor.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical fiber grating sensing, and particularly relates to an optical fiber grating displacement meter with an adjustable pre-stretching function. Background Art

[0002] Existing fiber Bragg grating displacement sensors are made based on beam-type strain sensors. For example, the grating is pasted on a cantilever beam. The displacement is transmitted through the connecting piece to bend the cantilever beam, thereby stretching or squeezing the fiber Bragg grating, causing a corresponding change in wavelength. The corresponding relationship between displacement and wavelength change is obtained, so that the displacement can be obtained through the change in the fiber Bragg grating wavelength.

[0003] For example, the Chinese utility model patent with application number: 200920029518.2 discloses a miniature fiber grating displacement sensor, including a transmission fiber, the transmission fiber is connected to a fiber grating, the fiber grating is connected to one end of a spring, the other end of the spring is connected to one end of a steel wire rope, and the other end of the steel wire rope is fixedly connected to a stator, wherein a protective device is provided outside the fiber grating and the spring, and a sleeve is provided outside the steel wire rope. The above utility model is based on an all-optical signal design and has no electronic devices, so it has good waterproof performance, no hidden dangers of electric sparks, and is resistant to electromagnetic interference; the above utility model is small in size and can be used for displacement measurement in a small space.

[0004] However, the fiber Bragg grating displacement sensor needs to be pre-stretched before use so that the fiber Bragg grating displacement sensor can measure tensile and compressive displacements. The above fiber Bragg grating displacement sensor cannot accurately adjust the pre-stretching amount and can only be pre-stretched within an approximate range. Utility Model Content

[0005] The utility model provides a fiber grating displacement meter with an adjustable pre-stretching function, aiming to solve the problem that the existing fiber grating displacement sensor cannot accurately adjust the pre-stretching amount.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A fiber Bragg grating displacement meter with an adjustable pre-stretching function comprises: a mounting box, a fiber Bragg grating displacement sensor and a tension sensor are slidably arranged inside the mounting box, the fiber Bragg grating displacement sensor and the tension sensor are connected via a connecting rod, the fiber Bragg grating displacement sensor is provided with a pull wire, the pull wire extends to the outside of the mounting box and is connected with a connecting ring, one end of the tension sensor which is rotatably connected with an adjusting rod on one side away from the fiber Bragg grating displacement sensor, the other end of the adjusting rod extends to the outside of the mounting box and is fixedly connected with a knob, the circumferential side wall of the adjusting rod is threadedly connected with the corresponding side wall of the mounting box, a locking device is arranged on the mounting box, and the locking device is used to lock the fiber Bragg grating displacement sensor; a display is arranged on the upper surface of the mounting box, and the display is used to display the measured value of the tension sensor, and connecting ears are arranged at the four corners of the mounting box.

[0008] Furthermore, sliders are provided on the upper and lower sides of the fiber grating displacement sensor and the tension sensor, and slide rails matching with the sliders are provided inside the installation box.

[0009] Furthermore, the locking device further includes: a locking rod fixedly arranged on the upper slider of the fiber grating displacement sensor, the locking rod extending to the outside of the installation box and threadedly connected with a locking nut, and an avoidance groove for avoiding the locking rod is opened on the installation box, and the diameter of the lower part of the locking nut is larger than the width of the avoidance groove.

[0010] Furthermore, the fiber grating displacement sensor further includes: a protective cover, one side of the protective cover is fixedly connected to one end of a connecting rod, the other side of the protective cover is provided with an outer tube, the side of the outer tube away from the protective cover is slidably connected to a sliding rod, the side of the sliding rod away from the outer tube is fixedly connected to one end of a pull wire, the other end of the pull wire extends to the outside of the installation box and is fixedly connected to a connecting ring, a sensing component is provided inside the protective cover and the outer tube, optical fiber leads are provided on the left and right sides of the protective cover, the optical fiber leads cooperate with the sensing component, and the sliding rod extends to the inside of the outer tube and cooperates with the sensing component.

[0011] Furthermore, sliders are fixedly connected to the upper and lower sides of the protective cover.

[0012] Furthermore, a protruding shaft is provided on the side of the tension sensor close to the fiber grating displacement sensor, and the protruding shaft is fixedly connected to the connecting rod. A rotating seat is provided on the side of the tension sensor away from the fiber grating displacement sensor, and the rotating seat is rotatably connected to one end of the adjusting rod.

[0013] Compared with the prior art, the utility model has the following technical effects:

[0014] 1. The fiber Bragg grating displacement meter with adjustable pre-stretching function described in the utility model can convert the pre-stretching of the fiber Bragg grating displacement sensor into the tension value of the tension sensor through the coordinated use of the tension sensor and the fiber Bragg grating displacement sensor, and display it on the display, so that the operator can intuitively feel the change of the pre-stretching amount of the fiber Bragg grating displacement sensor and adjust the pre-stretching amount of the fiber Bragg grating displacement sensor more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an internal schematic diagram of a fiber Bragg grating displacement meter with adjustable pre-stretching function described in the utility model;

[0016] Figure 2 It is a schematic diagram of an axial cross section of a fiber Bragg grating displacement meter with an adjustable pre-stretching function described in the utility model;

[0017] Figure 3 It is an external schematic diagram of a fiber Bragg grating displacement meter with an adjustable pre-stretching function described in the utility model.

[0018] In the figure: 1, installation box; 2, fiber Bragg grating displacement sensor; 201, protective cover; 202, outer cylinder; 203, sliding rod; 204, pull wire; 205, connecting ring; 206, optical fiber lead;

[0019] 3. Tension sensor; 301. Extension shaft; 302. Rotating seat;

[0020] 4. Adjustment rod; 5. Knob; 6. Slider; 7. Locking rod; 8. Locking nut; 9. Slide rail; 10. Avoidance groove; 11. Connecting ear; 12. Display; 13. Connecting rod. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in combination with the specific embodiments of the application and with reference to the accompanying drawings.

[0022] like Figure 1-3As shown, a fiber Bragg grating displacement meter with adjustable pre-stretching function comprises: a mounting box 1, a fiber Bragg grating displacement sensor 2 and a tension sensor 3 are slidably arranged inside the mounting box 1, the fiber Bragg grating displacement sensor 2 and the tension sensor 3 are connected by a connecting rod 13, the fiber Bragg grating displacement sensor 2 is provided with a pull wire 204, the pull wire 204 extends to the outside of the mounting box 1 and is connected with a connecting ring 205, one end of the tension sensor 3 away from the fiber Bragg grating displacement sensor 2 is rotatably connected with an adjusting rod 4, the other end of the adjusting rod 4 extends to the outside of the mounting box 1 and is fixedly connected with a knob 5, the circumferential side wall of the adjusting rod 4 is threadedly connected with the corresponding side wall of the mounting box 1, and a locking device is arranged on the mounting box 1, and the locking device is used to lock the fiber Bragg grating displacement sensor 2; a display 12 is arranged on the upper surface of the mounting box 1, and the display 12 is used to display the measured value of the tension sensor 3, and connecting ears 11 are arranged at the four corners of the mounting box 1.

[0023] The specific method of use is as follows: first, the connecting ring 205 is fixed to the point to be measured; after the installation box 1 is moved to a suitable position, the connecting ear 11 is fixed to the reference point through the cooperation of the fixing parts such as screws, so that the pull wire 204 is straightened; the pull wire 204 can be a steel wire rope with a low elastic deformation degree; after the installation box 1 is fixed, the position of the tension sensor 3 inside the installation box 1 can be adjusted by rotating the adjustment rod 4; the tension sensor 3 drives the fiber grating displacement sensor 2 to move through the connecting rod 13, so that the pre-stretching amount of the fiber grating displacement sensor 2 changes, and as the pre-stretching amount changes, the tension sensor 3 changes in the tension applied to the tension sensor 3, and is displayed on the display 12, so that the operator can intuitively feel the change in the pre-stretching amount; a processor can also be added to the installation box 1 to convert the tension applied to the tension sensor 3 into the displacement of the fiber Bragg grating displacement sensor 2 and then display it on the display 12, so as to avoid the operator from pre-stretching the fiber Bragg grating displacement sensor 2 when the pre-stretching amount exceeds the sensor range, resulting in damage to the sensor; after the sensor is pre-stretched, the sensor is locked by the locking device, and after the installation is completed, the sensor is detected by the corresponding detection device and the initial parameters are recorded.

[0024] like Figure 1-2 As shown, sliders 6 are provided on the upper and lower sides of the fiber Bragg grating displacement sensor 2 and the tension sensor 3, and a slide rail 9 matching with the slider 6 is provided inside the installation box 1. By providing the slider 6 and the slide rail 9, the friction between the fiber Bragg grating displacement sensor 2 and the tension sensor 3 and the installation box 1 can be effectively reduced, so that the tension detected by the tension sensor 3 is close to the actual tension generated by the pre-stretching of the fiber Bragg grating displacement sensor 2.

[0025] like Figure 1-2As shown, the locking device further comprises: a locking rod 7 fixedly arranged on the upper slider 6 of the fiber Bragg grating displacement sensor 2, the locking rod 7 extending to the outside of the installation box 1 and being threadedly connected with a locking nut 8, the installation box 1 is provided with an escape groove 10 for escaping the locking rod 7, and the diameter of the lower part of the locking nut 8 is greater than the width of the escape groove 10. The setting of the locking device can flexibly change the fixed state and the active state of the fiber Bragg grating displacement sensor 2, which is convenient for the operator to adjust.

[0026] like Figure 1 As shown, the fiber Bragg grating displacement sensor 2 further includes: a protective cover 201, one side of the protective cover 201 is fixedly connected to one end of the connecting rod 13, the other side of the protective cover 201 is provided with an outer cylinder 202, the side of the outer cylinder 202 away from the protective cover 201 is slidably connected to a sliding rod 203, the side of the sliding rod 203 away from the outer cylinder 202 is fixedly connected to one end of a pull wire 204, the other end of the pull wire 204 extends to the outside of the installation box 1 and is fixedly connected to a connecting ring 205, the inside of the protective cover 201 and the outer cylinder 202 are provided with a sensing component, the left and right sides of the protective cover 201 are provided with optical fiber leads 206, the optical fiber leads 206 cooperate with the sensing component, and the sliding rod 203 extends to the inside of the outer cylinder 202 and cooperates with the sensing component. The sensing component inside the fiber Bragg grating displacement sensor 2 is a mature prior art and will not be described in detail here.

[0027] like Figure 1-2 As shown, the upper and lower sides of the protective cover 201 are fixedly connected with sliders 6 .

[0028] like Figure 1 As shown, a protruding shaft 301 is provided on the side of the tension sensor 3 close to the fiber grating displacement sensor 2, and the protruding shaft 301 is fixedly connected to the connecting rod 13. A rotating seat 302 is provided on the side of the tension sensor 3 away from the fiber grating displacement sensor 2, and the rotating seat 302 is rotatably connected to one end of the adjusting rod 4.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A fiber Bragg grating displacement meter with adjustable pre-stretching function, characterized in that: include: An installation box (1), wherein a fiber Bragg grating displacement sensor (2) and a tension sensor (3) are slidably arranged inside the installation box (1), the fiber Bragg grating displacement sensor (2) and the tension sensor (3) are connected via a connecting rod (13), the fiber Bragg grating displacement sensor (2) is provided with a pull wire (204), the pull wire (204) extends to the outside of the installation box (1) and is connected to a connecting ring (205), and the tension sensor (3) is rotatably connected to an adjustment rod (4) on a side away from the fiber Bragg grating displacement sensor (2) The adjusting rod (4) is provided at one end thereof, the other end of the adjusting rod (4) extends to the outside of the installation box (1) and is fixedly connected to a knob (5), the circumferential side wall of the adjusting rod (4) is threadedly connected to the corresponding side wall of the installation box (1), and a locking device is provided on the installation box (1), and the locking device is used to lock the fiber optic Bragg grating displacement sensor (2); a display (12) is provided on the upper surface of the installation box (1), and the display (12) is used to display the measured value of the tension sensor (3), and connecting ears (11) are provided at the four corners of the installation box (1).

2. The fiber Bragg grating displacement meter with adjustable pre-stretching function according to claim 1, characterized in that: Slide blocks (6) are provided on both the upper and lower sides of the fiber grating displacement sensor (2) and the tension sensor (3), and a slide rail (9) matching the slide blocks (6) is provided inside the installation box (1).

3. The fiber Bragg grating displacement meter with adjustable pre-stretching function according to claim 2, characterized in that: The locking device further comprises: a locking rod (7) fixedly arranged on an upper slider (6) of the fiber optic grating displacement sensor (2), the locking rod (7) extending to the outside of the installation box (1) and being threadedly connected with a locking nut (8), an escape groove (10) for escaping the locking rod (7) being provided on the installation box (1), and the diameter of the lower part of the locking nut (8) being larger than the width of the escape groove (10).

4. The fiber Bragg grating displacement meter with adjustable pre-stretching function according to claim 2, characterized in that: The fiber Bragg grating displacement sensor (2) further comprises: a protective cover (201), one side of the protective cover (201) being fixedly connected to one end of a connecting rod (13), the other side of the protective cover (201) being provided with an outer cylinder (202), the side of the outer cylinder (202) away from the protective cover (201) being slidably connected to a sliding rod (203), the side of the sliding rod (203) away from the outer cylinder (202) being fixedly connected to one end of a pull wire (204), the other end of the pull wire (204) extending to the outside of the installation box (1) and fixedly connected to a connecting ring (205), the inside of the protective cover (201) and the outer cylinder (202) being provided with a sensing component, the left and right sides of the protective cover (201) being provided with optical fiber leads (206), the optical fiber leads (206) cooperating with the sensing component, and the sliding rod (203) extending to the inside of the outer cylinder (202) and cooperating with the sensing component.

5. The fiber Bragg grating displacement meter with adjustable pre-stretching function according to claim 4, characterized in that: Slide blocks (6) are fixedly connected to both the upper and lower sides of the protective cover (201).

6. The fiber Bragg grating displacement meter with adjustable pre-stretching function according to claim 1, characterized in that: A protruding shaft (301) is provided on a side of the tension sensor (3) close to the fiber optic Bragg grating displacement sensor (2), the protruding shaft (301) is fixedly connected to the connecting rod (13), and a rotating seat (302) is provided on a side of the tension sensor (3) away from the fiber optic Bragg grating displacement sensor (2), the rotating seat (302) is rotatably connected to one end of the adjusting rod (4).

Images