A welding device and method for fiber bragg grating pressure rings

Abstract

The application relates to the technical field of welding, in particular to a fiber grating pressure ring welding device and method, which comprises a base, a pneumatic module is arranged on one side of the base through a mounting frame, the front end of the pneumatic module is connected with a welding gun and can drive the welding gun to automatically move positions, a placing groove is further arranged at the front end of the mounting frame, the placing groove is used for placing a metal ring, an installation groove is arranged in the metal ring, a fiber grating is packaged on a standard base to obtain a fiber grating strain sensitive element, the installation groove is used for placing the fiber grating strain sensitive element, an energy storage type pulse cold welding machine is further arranged on the base, the energy storage type pulse cold welding machine grounding clamp is connected with the base, and a pre-prepared steel sheet type fiber grating strain sensitive element is welded to the body of a force main body, the mechanical performance of the welding joint is guaranteed, the consistency of stress and strain transmission is greatly improved, the production efficiency is improved, and the performance of the sensor is improved.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and specifically to a welding apparatus and method for a fiber optic grating pressure ring. Background Technology

[0002] Fiber Bragg grating strain sensors, as core sensing components of modern structural health monitoring systems, are widely used in key fields such as aerospace, energy and power, civil engineering, and heavy machinery due to their superior characteristics such as resistance to electromagnetic interference, corrosion resistance, and ease of network-based distributed measurement. Essentially, they are standardized functional modules that directly and reliably sense mechanical strain by engineering-encapsulating wavelength-sensitive fiber Bragg gratings.

[0003] Currently, the mainstream method for installing such sensitive elements into metal load-bearing structures (such as pressure rings, steel beams, pipes, shells, etc.) is to mill grooves or drill holes in the metal load-bearing body, and use high-strength adhesives such as epoxy resin to directly paste, embed, and seal the bare fiber grating or simply packaged sensitive element inside or on the surface of the structure.

[0004] However, the use of adhesives can lead to problems such as adhesive curing shrinkage, uneven internal stress, and residual air bubbles, which can easily cause the sensor sensitivity coefficient to be discrete and the zero point to drift to be large, seriously affecting the consistency, stability and pass rate of product performance during mass production. Summary of the Invention

[0005] In view of the problems raised in the background art, the present invention provides a welding device and method for fiber optic grating pressure rings to solve the problems, and the present invention will be further described below.

[0006] A welding device for a fiber Bragg grating pressure ring includes a base. A pneumatic module is mounted on one side of the base via a mounting bracket. The front end of the pneumatic module is connected to a welding torch and can drive the welding torch to move automatically. A placement groove is also provided at the front end of the mounting bracket for placing a metal ring. An installation groove is formed in the metal ring. The fiber Bragg grating is encapsulated onto a standard base to obtain a fiber Bragg grating strain-sensitive element. The installation groove is used to place the fiber Bragg grating strain-sensitive element. An energy storage pulse cold welding machine is also provided on the base, and the grounding clamp of the energy storage pulse cold welding machine is connected to the base.

[0007] Preferably, the base is made of 4J36 iron-nickel alloy.

[0008] Preferably, the metal ring is made of 45 steel.

[0009] A welding method for a fiber Bragg grating pressure ring includes the following steps:

[0010] S1: Package the fiber Bragg grating onto a standard base to obtain a standard fiber Bragg grating strain-sensitive element, ready for use;

[0011] S2: An installation groove is opened inside the metal ring, and ultrasonic testing and magnetic particle testing are used to inspect the internal quality of the installation groove and the surface quality of the fiber optic strain-sensitive element, respectively, to ensure that there are no defects in the area to be welded that would affect the welding quality.

[0012] S3: The fiber optic strain sensor is installed into the mounting trench.

[0013] S4: The fiber optic strain-sensitive element is welded to the metal ring using an energy storage pulse cold welding machine. During the welding process, the movement of the welding gun is controlled by a pneumatic module to ensure the accuracy of the weld point position and the consistency of the weld point spacing.

[0014] S5: Stress-relief annealing treatment for fiber Bragg grating pressure rings.

[0015] Preferably, in step S1, the thickness of the base is 1.2 mm.

[0016] Preferably, in step S3: the gap between the base and the mounting groove is ≤0.5mm, and the base and the mounting groove have the same height.

[0017] Preferably, in step S4: the energy storage pulse cold welding machine is of model SZ-1800, with a power of 1200W, a pulse current of 20-30A, a pulse time of 20ms, and an output mode of arc welding output.

[0018] Preferably, in step S4: the tungsten needle diameter of the welding torch (4) is 1.6 mm, the distance between the tungsten needle and the welding point is 1-3 mm, ensuring that the welding point diameter is 3-5 mm, the tungsten needle protrudes 3-5 mm from the nozzle, the protective gas is high-purity argon gas of 99.99% Ar, and the gas flow rate is 5-10 L / min.

[0019] Preferably, in step S5, the stress-relief annealing process parameters are: holding temperature 70℃, heating rate 40℃ / h, holding time 96h, and furnace cooling to room temperature.

[0020] Beneficial effects: Compared with the prior art, this invention uses pre-fabricated steel sheet fiber grating strain sensing elements with welding materials and welding methods that match the stress-bearing body, controls the welding points and selects appropriate welding process parameters, and welds the pre-fabricated steel sheet fiber grating strain sensing elements to the body of the stress-bearing body. This not only ensures the mechanical properties of the welded joint but also greatly improves the consistency of stress and strain transmission, increases production efficiency, and improves the performance of the sensor. The use of internal groove design and welding sequence control ensures the installation accuracy of the steel sheet fiber grating strain sensing elements and reduces welding stress deformation, improving the consistency of stress and strain transmission to the grating. The post-weld overall stress-relief annealing treatment reduces the internal stress of the weld and the entire fiber grating pressure ring. Attached Figure Description

[0021] Figure 1 : Schematic diagram of the structure of the present invention;

[0022] In the diagram: 1. Base; 2. Metal ring; 3. Pneumatic module; 4. Welding gun; 5. Fiber grating strain sensitive element. Detailed Implementation

[0023] Next, we will combine the appendix Figure 1 A specific embodiment of the present invention will be described in detail below.

[0024] A welding device for a fiber Bragg grating pressure ring includes a base 1. A pneumatic module 3 is mounted on one side of the base 1 via a mounting bracket. The front end of the pneumatic module 3 is connected to a welding torch 4 and can drive the welding torch to move automatically. This technology is prior art and will not be elaborated further here. A placement groove is also provided at the front end of the mounting bracket 1 for placing a metal ring 2. In this embodiment, the metal ring 2 is made of 45 steel. An installation groove is opened in the metal ring 2. The fiber Bragg grating is encapsulated onto a standard base to obtain a fiber Bragg grating strain sensitive element. The installation groove is used to place the fiber Bragg grating strain sensitive element 5. The base is made of 4J36 iron-nickel alloy. In this embodiment, an energy storage pulse cold welding machine is also provided on the base 1, and the grounding clamp of the energy storage pulse cold welding machine is connected to the base 1.

[0025] A welding method for a fiber Bragg grating pressure ring includes the following steps:

[0026] S1: Package the fiber Bragg grating onto a standard base to obtain a standard fiber Bragg grating strain-sensitive element, ready for use;

[0027] S2: An installation groove is opened inside the metal ring 2, and ultrasonic testing and magnetic particle testing are used to test the internal quality of the installation groove and the surface quality of the fiber optic strain-sensitive element, respectively, to ensure that there are no defects in the area to be welded that would affect the welding quality.

[0028] S3: The fiber optic strain sensor is installed into the mounting trench.

[0029] S4: The fiber optic strain-sensitive element is welded to the metal ring 2 using an energy storage pulse cold welding machine. During the welding process, the movement of the welding gun is controlled by pneumatic or pneumatic module to ensure the accuracy of the weld point position and the consistency of the weld point spacing.

[0030] S5: Stress relief annealing treatment of the welded fiber grating pressure ring is performed using a stress relief annealing furnace or insulation box.

[0031] In this embodiment: in step S1: the thickness of the base is 1.2 mm;

[0032] In step S3: the gap between the base and the mounting groove is ≤0.5mm, and the base and the mounting groove have the same height;

[0033] In step S4: the energy storage pulse cold welding machine is model SZ-1800, with a power of 1200W, a pulse current of 20-30A, a pulse time of 20ms, and an output mode of arc welding output;

[0034] In step S4: the tungsten needle diameter of the welding torch 4 is 1.6 mm, the distance between the tungsten needle and the welding point is 1-3 mm, ensuring that the welding point diameter is 3-5 mm, the tungsten needle protrudes 3-5 mm from the nozzle, the protective gas is high-purity argon gas of 99.99% Ar, and the gas flow rate is 5-10 L / min; the size of the welding point is controlled, thereby improving the consistency of stress and strain transmission from the stressed body to the grating;

[0035] In step S5: the stress-relief annealing process parameters are: holding temperature 70℃, heating rate 40℃ / h, holding time 96h, and furnace cooling to room temperature;

[0036] This invention employs pre-fabricated steel sheet fiber Bragg grating strain sensing elements with matching welding materials and methods to the load-bearing body. By controlling the welding points and selecting appropriate welding process parameters, the pre-fabricated steel sheet fiber Bragg grating strain sensing elements are welded onto the main body of the load-bearing body. This significantly improves the consistency of stress and strain transmission while ensuring the mechanical properties of the weld joint, thereby increasing production efficiency and enhancing sensor performance. The use of internal groove design and welding sequence control ensures the installation accuracy of the steel sheet fiber Bragg grating strain sensing elements and reduces welding stress deformation, improving the consistency of stress and strain transmission to the grating. Post-weld overall stress-relief annealing reduces the internal stress in the weld and the entire fiber Bragg grating pressure ring.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A welding method for a fiber Bragg grating pressure ring, applicable to a welding device for a fiber Bragg grating pressure ring, the welding device including a base (1), a pneumatic module (3) is mounted on one side of the base (1) via a mounting bracket, the front end of the pneumatic module (3) is connected to a welding torch (4) and can drive the welding torch (4) to move automatically, a placement groove is also provided at the front end of the base (1), the placement groove is used to place a metal ring (2), an installation groove is opened in the metal ring (2), the fiber Bragg grating is encapsulated on a standard base to obtain a fiber Bragg grating strain sensitive element (5), the installation groove is used to place the fiber Bragg grating strain sensitive element (5), an energy storage pulse cold welding machine is also provided on the base (1), and the grounding clamp of the energy storage pulse cold welding machine is connected to the base (1), the base is made of 4J36 iron-nickel alloy, and the metal ring (2) is made of 45 steel; Its features are: The welding method includes the following steps: S1: Encapsulate the fiber grating onto a standard base to obtain a standard fiber grating strain-sensitive element (5), for later use; S2: An installation groove is opened inside the metal ring (2), and ultrasonic testing and magnetic particle testing are used to test the internal quality of the installation groove and the surface quality of the fiber optic strain sensitive element, respectively, to ensure that there are no defects in the area to be welded that affect the welding quality. S3: The fiber optic strain sensing element (5) is installed into the mounting trench; S4: The fiber optic strain sensing element (5) is welded to the metal ring (2) using an energy storage pulse cold welding machine. During the welding process, the movement of the welding gun (4) is controlled by the pneumatic module (3) to ensure the accuracy of the welding point position and the consistency of the welding point spacing. S5: Stress-relief annealing treatment for fiber Bragg grating pressure rings.

2. The welding method for a fiber optic grating pressure ring according to claim 1, characterized in that: In step S1: the thickness of the base is 1.2 mm.

3. The welding method for a fiber optic grating pressure ring according to claim 1, characterized in that: In step S3: the gap between the base and the mounting groove is ≤0.5mm, and the base and the mounting groove have the same height.

4. The welding method for a fiber optic grating pressure ring according to claim 1, characterized in that: In step S4: the energy storage pulse cold welding machine is model SZ-1800, with a power of 1200W, a pulse current of 20-30A, a pulse time of 20ms, and an output mode of arc welding output.

5. The welding method for a fiber optic grating pressure ring according to claim 1, characterized in that: In step S4: the tungsten needle diameter of the welding torch (4) is 1.6 mm, the distance between the tungsten needle and the welding point is 1-3 mm, ensuring that the welding point diameter is 3-5 mm, the tungsten needle protrudes 3-5 mm from the nozzle, the protective gas is 99.99% Ar high-purity argon gas, and the gas flow rate is 5-10 L / min.

6. The welding method for a fiber optic grating pressure ring according to claim 1, characterized in that: In step S5: the stress-relief annealing process parameters are: holding temperature 70℃, heating rate 40℃ / h, holding time 96h, and furnace cooling to room temperature.

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