CN102252776B - High-temperature curing device for fiber bragg grating sensor - Google Patents

Abstract

A fiber grating sensor high-temperature curing device, a slide bar is provided at the upper end of the base bracket, the left end of the slide bar is provided with a left clamping frame that moves left and right along the slide bar, and the right end is provided with a right clamping frame that moves left and right along the slide bar, The lower part of the left clamping frame is provided with the left fixed clamp for optical fiber moving up and down, and the lower part of the right clamping frame is provided with the right fixed clamp for optical fiber moving up and down. The device and the operating platform frame for placing the substrate of the sensor to be packaged are provided with a temperature controller connected to the heating device through wires on the frame. The invention has the advantages of small size, simple structure, low energy consumption, easy operation, etc., can be used in the temperature range of 60-550°C, and realizes high-temperature curing and encapsulation of the optical fiber grating sensor. The invention can also be used on other small devices or components that need high temperature bonding.

Description

Fiber Bragg grating sensor high temperature curing device

technical field

The invention belongs to the technical field of optical fiber sensors, and in particular relates to a high-temperature curing device for optical fiber grating sensors.

Background technique

As a new type of optical passive device, fiber grating sensor has become a research field in the field of sensing due to its advantages of anti-electromagnetic interference, small size, light weight, corrosion resistance, and easy realization of wavelength division, time division and space division multiplexing. emerging topics. The optical fiber grating sensor uses the characteristics that the optical fiber grating changes with the external physical quantity, such as the change of pressure, temperature and strain, which will cause the central wavelength shift of the reflection spectrum or transmission spectrum. The measurement of the physical quantity can be realized by detecting the wavelength shift. The response sensitivity of bare fiber Bragg grating to temperature and strain is very low. In addition, bare fiber Bragg grating itself is very thin and low in strength. It cannot be used as a sensor directly to meet the requirements of various engineering applications with different measurement ranges and extensive construction and installation. Therefore, functional encapsulation of bare fiber gratings is necessary to achieve protection of fiber gratings and sensitivity to temperature and strain responses, so as to meet the requirements of on-site construction and sensor sensitivity of large engineering structures. When the fiber grating sensor is used in a high-temperature working environment, it is necessary to use a high-temperature curing agent to fix the fiber grating on the base material, so corresponding thermal curing equipment is required. The commonly used thermal curing equipment is an oven. At present, the maximum heating temperature of domestic ovens is 400 °C, the continuous use of the oven at the highest temperature consumes energy and is prone to equipment failure. Therefore, it is necessary to design a small, low-energy, and multi-functional fiber grating high-temperature curing device to meet the needs of high-temperature packaging of fiber grating sensors.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of existing thermal curing equipment and provide a high temperature curing device for fiber grating sensors with reasonable design, simple structure, convenient operation and low energy consumption.

The technical solution adopted to solve the above technical problems is: a slide bar is provided at the upper end of the base bracket, the left end of the slide bar is provided with a left clamping frame that moves left and right along the slide bar, and the right end is provided with a right clamping frame that moves left and right along the slide bar. The lower part of the left clamping frame is provided with the left fixed clamp of the optical fiber moving up and down, and the lower part of the right clamping frame is provided with the right fixed clamp of the optical fiber moving up and down. There is a heating device and an operating platform frame for placing the substrate of the sensor to be packaged, and a temperature controller connected to the heating device through wires is arranged on the frame.

The heating device of the present invention is as follows: the heating device fixing frame is arranged on the slide bar, the right side of the heating device fixing frame on the sliding bar is provided with a ring frame, the heating device fixing frame lower part is provided with a heating base processed with through holes, and the right end of the heating base is There is an outer casing with the right end connected to the ring frame, and a heating inner tube with a resistance wire wound on the outer surface is arranged in the outer casing at the right end of the heating base, and a temperature sensor is arranged in the heating inner tube.

The outer sleeve and heating inner tube of the present invention are quartz glass tubes.

The operating platform frame of the present invention is as follows: the fixed block is arranged on the slide bar, the bottom of the fixed block is provided with a platform bar, and the bottom of the platform bar is provided with an operating platform for placing the substrate of the sensor to be packaged.

The invention adopts the resistance wire spirally wound on the heating inner tube as a high-temperature heat source, and the outer tube is a thermal insulation tube. The sensor base for packaging is placed on the operating platform, and the optical fiber with the optical fiber grating written on it is placed on the sensor base. The two ends of the optical fiber are fixed on the left clamping frame and the right clamping frame. By adjusting the vertical position of the operating platform, the height of the sensor base and the optical fiber is adjusted to a suitable position. By adjusting the horizontal position of the operating platform frame, Therefore, the sensor base and the optical fiber are axially inserted into the heating inner tube to realize high-temperature packaging. The invention has the advantages of small size, simple structure, low energy consumption, easy operation, etc., can be used in the temperature range of 60-550°C, and realizes high-temperature curing and encapsulation of the optical fiber grating sensor. The invention can also be used on other small devices or components that need high temperature bonding.

Description of drawings

Fig. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of the heating device 3 in FIG. 1 .

FIG. 3 is a schematic structural view of the operating platform frame 5 in FIG. 1 .

Fig. 4 is the response curve of the quartz substrate fiber grating temperature sensor packaged by the present invention.

Fig. 5 is a spectrogram of the quartz substrate fiber grating temperature sensor packaged in the present invention.

Fig. 6 is the response curve of the beryllium copper substrate fiber grating temperature sensor packaged in the present invention.

Fig. 7 is a spectrogram of the beryllium copper substrate fiber grating temperature sensor packaged in the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and various embodiments, but the present invention is not limited to these embodiments.

Example 1

In Fig. 1, the fiber grating sensor high-temperature curing device of this embodiment is connected by a base bracket 1, a left clamping frame 2, a heating device 3, a slide bar 4, an operating platform frame 5, a right clamping frame 6, and a temperature controller 7 constitute.

On the upper part of the U-shaped base bracket 1, there are 2 parallel horizontal slide bars 4 connected by threads. The left clamping frame 2 is installed on the left end of the slide bar 4 and can move left and right along the slide bar 4. The lower part is the left fixing clip 2-1 of the optical fiber. The left holder 2 is threadedly connected with a height adjustment screw. The height of the left fixing clip 2-1 of the optical fiber can be adjusted up and down. Fixed at the required height, the left optical fiber fixing clip 2-1 is threadedly connected with a fastening screw, and the fastening screw on the left optical fiber fixing clip 2-1 is used to fix the left end of the fiber grating 8. The right clamping frame 6 is installed on the right end of the slide bar 4, and can move left and right along the slide bar 4. The lower part of the right clamping frame 6 is the right fixing clip 6-1 for the optical fiber, and the right clamping frame 6 is threadedly connected with a height adjustment screw , the height of the right optical fiber fixing clip 6-1 can be adjusted up and down, the right optical fiber fixing clip 6-1 can be fixed at the required height by adjusting the height adjusting screw, the right optical fiber fixing clip 6-1 is threadedly connected with a fastening screw, The fastening screw of the right fixing clip 6-1 of the optical fiber is used to fix the right end of the fiber grating 8. A heating device 3 is installed on the right side of the left clamping frame 2 on the slide bar 4, and the heating device 3 can move left and right along the slide bar 4. When packaging, the left end of the fiber grating 8 is fixed on the left fiber grating 2 through the heating device 3- 1. The right end of the fiber grating 8 is fixed on the right fiber fixing clamp 6-1 of the right clamping frame 6. An operating platform frame 5 is installed on the right side of the heating device 3 on the slide bar 4, and the operating platform frame 5 can move left and right along the slide bar 4, and the operating platform frame 5 is used to place the sensor substrate to be packaged. The lower part of the support 1 is fixedly connected with a temperature controller 7 with a threaded fastening connector, and the temperature controller 7 is connected to the heating device 3 through a wire.

In Fig. 1, 2, the heating device 3 of the present embodiment is made up of heating device fixing frame 3-1, heating base 3-2, outer casing 3-3, ring frame 3-4, heating inner tube 3-5, resistance Wire 3-6 and temperature sensor 3-7 are connected to form.

The heating device fixed mount 3-1 is installed on the slide bar 4, and the right side of the heating device fixed mount 3-1 on the slide bar 4 is equipped with the ring frame 3-4, the heating device fixed mount 3-1, the ring frame 3-4 The height position can be adjusted, and the heating device fixing frame 3-1 and the suspension ring frame 3-4 can move left and right along the slide bar 4, and the heating base 3-2 is installed with fastening screws at the bottom of the heating device fixing frame 3-1, and the heating The base 3-2 is processed with a horizontal through hole for the fiber grating 8 to pass through, and the outer casing 3-3 is bonded to the right end of the heating base 3-2 with TS767 glue, which is sold by Beijing Tianshan New Material Technology Co., Ltd. The right end of the outer casing 3-3 is installed on the ring frame 3-4, and the right end of the heating base 3-2 in the outer casing 3-3 is bonded with the heating inner tube 3-5, the heating base 3-2, and the outer casing with TS767 glue. The axes of the tube 3-3 and the heating inner tube 3-5 coincide, and the outer surface of the heating inner tube 3-5 is wound with a spirally arranged resistance wire 3-6, and the resistance wire 3-6 is connected to the temperature controller 7 through a wire , the outer sleeve 3-3 and the heating inner tube 3-5 of the present embodiment are transparent quartz glass tubes, and the heating base 3-2, the outer sleeve 3-3 and the heating inner tube 3-5 can be designed to be different according to different requirements. The geometric dimensions are replaced, and a temperature sensor 3-7 is arranged in the heating inner tube 3-5. The temperature sensor 3-7 is connected to the temperature controller 7 through a wire, and the temperature sensor 3-7 converts the received temperature signal into an electrical signal. The signal is output to the temperature controller 7, and the temperature controller 7 controls the connection or disconnection of the resistance wire 3-6 with the power supply according to the preset temperature, so as to realize automatic control of the curing temperature.

In Fig. 3, the operating platform frame 5 of this embodiment is composed of a fixed block 5-1, an operating platform 5-2, and a platform bar 5-3. The fixed block 5-1 is installed on the slide bar 4 and can slide along the The rod 4 moves left and right, and the bottom of the fixed block 5-1 is fixed with a fastening screw to install a platform rod 5-3, and the bottom of the platform rod 5-3 is welded and connected with an operating platform 5-2. When packaging, the sensor base 5-4 to be packaged Placed on the operating platform 5-2, the fiber grating 8 to be packaged is placed on the sensor base 5-4 to be packaged, the operating platform 5-2 can move up and down in the vertical direction, and the fixed block 5-1 is connected with a tight Fastening screw, fastening screw is used for fixing the position of operating platform 5-2.

Working process of the present invention is as follows:

When encapsulating the optical fiber grating sensor, tighten the fastening screw of the left optical fiber fixed clip 2-1 at the lower end of the left clamping frame 2, and fix the left end of the fiber grating 8 on the left optical fiber fixed clip 2-1 of the left clamping frame 2, Tighten the fastening screw of the right optical fiber fixing clip 6-1 at the lower end of the right clamping frame 6, and fix the right end of the fiber grating 8 on the right optical fiber fixing clip 6-1 of the right clamping frame 6, and the sensor substrate to be packaged 5-4 Place it on the operating platform 5-2, and adjust the operating platform 5-2 so that the fiber grating 8 is in contact with the sensor substrate 5-4. Moving the left clamping frame 2 and the right clamping frame 6 applies prestress to the fiber grating 8 . Coat the bonding position of the fiber grating 8 and the sensor substrate 5-4 with curing agent, move the heating device 3 so that the position coated with the curing agent is located in the middle of the heating inner tube 3-5, and insert it into the heating inner tube 3-5 Temperature sensor 3-7, adjust the position of the temperature sensor 3-7, make it close to the bonding position, adjust the current and voltage through the resistance wire 3-6 to obtain the required curing temperature, and make the temperature of the curing process through the temperature controller 7 Keep it stable, and heat it according to the heating time required by the curing agent to complete the high-temperature bonding package of the sensor to be packaged.

In order to verify the beneficial effect of the present invention, the inventor adopts the high-temperature fiber grating temperature sensor packaged in Embodiment 1 of the present invention to carry out laboratory research experiments, and various experimental conditions are as follows:

Experimental equipment: spectrum analyzer, model AQ6319, produced by Japan Yokogawa; broadband light source, model ASE-CL, produced by Shenzhen Langguang Company; vacuum drying oven, model DZ-1BC, produced by Tianjin Test Company Production.

1. Using the present invention to package the quartz substrate fiber grating temperature sensor

Fiber Bragg grating temperature sensor structure: rectangular quartz substrate, length × width × height is 30mm × 8mm × 2mm, left and right pigtails are left at both ends, and the length is 600mm.

The optical fiber grating sensor high-temperature curing device prepared by the embodiment 1 of the present invention is used to package the optical fiber grating 8 on the quartz substrate, and the response curve of the wavelength of the optical fiber grating temperature sensor with temperature after packaging is shown in Figure 4, and the optical fiber grating temperature sensor is tested with a spectrum analyzer. The spectrum of the fiber grating temperature sensor is shown in Figure 5. As can be seen from Fig. 4, the peak wavelength of the quartz substrate fiber grating temperature sensor packaged in the present invention has a linear relationship with the temperature, and the fitting equation for testing the peak wavelength is:

λ=0.0125t+1555.0013(nm)

The temperature response sensitivity is 0.0125nm/℃; the linear fitting degree is:

R ² =0.9989

It can be seen from Figure 5 that the central wavelength λ of the packaged fiber grating temperature sensor at room temperature is 1555.4006nm, and the 3dB bandwidth is 0.1984nm. flap effect.

2. Using the present invention to package the beryllium bronze substrate fiber grating temperature sensor

The structure of the fiber grating temperature sensor: the outer diameter of the beryllium bronze tube base is 4mm, the wall thickness is 1mm, left and right pigtails are left at both ends, and the length is 1200mm.

Adopt the fiber grating sensor high-temperature curing device prepared by the embodiment 1 of the present invention to package the fiber grating in the beryllium copper substrate tube, and the response curve of the wavelength of the fiber grating temperature sensor with temperature after packaging is shown in Fig. The spectrum of the fiber grating temperature sensor is shown in Figure 7. As can be seen from Fig. 6, the peak wavelength of the fiber grating temperature sensor of the beryllium bronze substrate tube packaged by the present invention has a linear relationship with the temperature, and the test peak wavelength fitting equation is:

λ=0.0314t+1573.7236(nm)

The temperature response sensitivity is 0.0314nm/℃, and the linear fitting degree is:

R ² =0.9989

It can be seen from Figure 7 that the central wavelength λ of the packaged fiber grating temperature sensor at room temperature is 1574.4984nm, and the 3dB bandwidth is 0.2345nm. flap effect.

Claims (2)

1. A fiber grating sensor high-temperature curing device, two slide bars (4) are arranged on the upper end of the base bracket (1), and the left end of the slide bar (4) is provided with a left clamping frame that moves left and right along the slide bar (4) (2), the right end is provided with a right clamping frame (6) that moves left and right along the slide bar (4), and the left clamping frame (2) is provided with a left fixed clamp (2-1) and a right clamping frame for optical fibers moving up and down at the bottom of the left clamping frame (2). (6) The right fixing clamp (6-1) for the optical fiber moving up and down is arranged at the lower part, and a heating device is arranged in sequence from left to right between the left clamping frame (2) and the right clamping frame (6) on the slide bar (4) (3) and an operating platform frame (5) for placing the sensor base (5-4) to be packaged, the base support (1) is provided with a temperature controller (7) connected to the heating device (3) through wires; its characteristics Said heating device (3) is: the heating device fixing frame (3-1) is arranged on the slide bar (4), and the right side of the heating device fixing frame (3-1) on the sliding bar (4) is provided with a ring bracket (3-4), the bottom of the heating device fixed frame (3-1) is provided with a heating base (3-2) that is processed with a through hole, and the right end of the heating base (3-2) is provided with a right end that is connected to the ring frame (3 -4) the outer casing (3-3) on the heating base (3-2) is provided with a heating inner tube (3- 5), the heating inner tube (3-5) is provided with a temperature sensor (3-7). 2. The high-temperature curing device for fiber grating sensors according to claim 1, characterized in that: said outer casing (3-3) and heating inner tube (3-5) are quartz glass tubes.

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