A tube bender and bending straightening system for fiber optic splicing tubes

Abstract

The utility model provides a kind of for optical fiber splicing tube's pipe bender and bending straightening system, including opposite fixed upper die holder and lower die holder, the opposite face of upper die holder and lower die holder is equipped with matching arc positioning groove, space formed by two arc positioning grooves is equipped with gasket, upper roller and lower roller are equipped between upper die holder and lower die holder, and upper roller and lower roller are respectively located above and below arc positioning groove, and contact with optical fiber splicing tube surface, lower roller is fixedly connected with lower die holder, upper roller is pressed with lower die holder and upper roller can rotate relative to lower die holder, and power element for driving upper roller to rotate to make optical fiber splicing tube bend is further connected on lower die holder.The pipe bender adopts the combination structure form of detachable upper die holder and lower die holder, replaces overall extrusion by local contact bending, avoids optical fiber directly under pressure, and gasket is designed to absorb and disperse lateral shear force suffered by optical fiber splicing tube bending, to greatly reduce the risk of optical fiber damage.

Description

Technical Field

[0001] This utility model belongs to the technical field of auxiliary processing equipment for optical fiber splice tubes, specifically relating to a tube bender and bending straightening system for optical fiber splice tubes. Background Technology

[0002] During the connection process between the fiber optic pressure gauge and the optical cable in the oil well, the fiber optic splice tube needs to be pre-bent into an arc shape consistent with the optical cable reel to achieve the overall reel transportation of the fiber optic pressure gauge, splice tube, and optical cable; after the optical cable arrives at the well site, the splice tube is straightened and directly lowered into the well for operation.

[0003] While various general-purpose metal pipe benders are available on the market, specialized bending devices for fiber optic splice pipes in oil wells still face key technological bottlenecks:

[0004] (1) The risk of fiber damage is prominent: During the bending process, conventional tube benders can easily cause excessive stress on the fiber splice inside the splice tube, which can lead to microcracks in the fiber or misalignment of the splice (actual test data shows that the fiber loss increases by 30%-50% after the operation of ordinary tube benders), which can directly cause optical signal interruption in severe cases.

[0005] (2) Lack of adaptation to oil scenarios: According to market research and patent search, there is no high-pressure resistant and light-loss resistant fiber optic splice tube bending device designed specifically for oil well operations in China. Existing products can only meet the bending needs of ordinary metal pipes in conventional industrial environments.

[0006] (3) Technological gap positioning: The downhole environment of oil wells has special requirements for the bending accuracy (arc deviation needs to be controlled within ±5%), compressive strength (must withstand downhole pressure of more than 40MPa) and light loss resistance (fiber insertion loss ≤0.3dB) of fiber optic splice tubes. Existing general-purpose tube benders cannot meet the above three requirements, forming a significant technological gap. Utility Model Content

[0007] The purpose of this invention is to provide a tube bender for fiber optic splice tubes, which can at least solve some of the defects existing in the prior art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A bender for fiber optic splice tubes includes an upper mold base and a lower mold base fixed at a relative distance. Matching arc-shaped positioning grooves for the fiber optic splice tube to pass through are provided on the opposing surfaces of the upper and lower mold bases. A pad for absorbing and dispersing the lateral shear force experienced by the fiber optic splice tube during bending is provided within the space enclosed by the two arc-shaped positioning grooves. An upper roller and a lower roller are provided between the upper and lower mold bases, respectively located above and below the arc-shaped positioning grooves and in contact with the surface of the fiber optic splice tube. The lower roller is fixedly connected to the lower mold base. The upper roller is pressed against the lower mold base and can rotate relative to the lower mold base. A power component is also connected to the lower mold base to drive the upper roller to rotate, thereby bending the fiber optic splice tube.

[0010] Furthermore, the power component is a servo motor, and the upper roller and the lower mold base are pressed together by a connecting shaft, which is connected to the servo motor by a coupling.

[0011] Furthermore, the lower mold base is provided with a pull rod for manually rotating the upper roller.

[0012] Furthermore, the lower mold base has an air pressure hole on its side facing away from the upper mold base, and the air pressure hole is connected to the arc-shaped positioning groove on the lower mold base.

[0013] Furthermore, the pad is two semi-circular beryllium bronze sleeves, which hold the outer surface of the optical fiber splice tube.

[0014] Furthermore, the arc length of the arc-shaped positioning groove is 1 / 3 of the circumference of the outer wall of the optical fiber splice tube.

[0015] In addition, this utility model also provides a bending and straightening system for optical fiber splice tubes, including several sets of the above-mentioned tube benders, and a stress monitoring component for monitoring the strain of the bent section of the optical fiber splice tube; each of the tube benders is distributed at equal intervals along the axial direction of the optical fiber splice tube, and the stress monitoring component includes a fiber optic grating and a grating demodulator, the fiber optic grating passes through the optical fiber splice tube, and the exit end of the fiber optic grating is connected to the grating demodulator.

[0016] Furthermore, the exit end of the optical fiber in the optical fiber splice tube is connected to an optical time domain reflectometer for real-time monitoring of optical fiber insertion loss.

[0017] Furthermore, the aforementioned bending and straightening system also includes a tooling platform for supporting each of the pipe benders. The tooling platform is equipped with a dual laser displacement sensor and an angle encoder for real-time calculation of the three-dimensional trajectory deviation of the centerline of the fiber optic splice pipe.

[0018] Furthermore, the aforementioned bending straightening system also includes a shape memory alloy clamp for bending and shaping the bent fiber optic splice tube.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] (1) The fiber optic splice tube bender provided by this utility model adopts a detachable upper mold base and lower mold base combination structure. It replaces the overall compression by local contact bending, avoiding direct pressure on the fiber optic cable. At the same time, a pad is designed to absorb and disperse the lateral shear force on the fiber optic splice tube during bending, thereby greatly reducing the risk of fiber optic cable damage.

[0021] (2) The bending and straightening system for optical fiber splice tubes provided by this utility model uses multiple sets of tube benders to apply pressure to the optical fiber splice tube segment by segment. At the same time, with the design of the liner, the lateral shear force borne by the optical fiber splice point is converted into uniform axial stress by using a multi-level stress dispersion bending method. Furthermore, the stress monitoring component is used to monitor the stress state of the optical fiber splice tube in real time during the bending process, ensuring that the bending stress is within a safe threshold and greatly reducing the risk of optical fiber damage.

[0022] The present invention will be further described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the pipe bender in an embodiment of this utility model;

[0024] Figure 2 This is a cross-sectional schematic diagram of the pipe bender in an embodiment of this utility model;

[0025] Figure 3 This is a schematic diagram of the bending straightening system in an embodiment of this utility model;

[0026] Figure 4 This is a front view of the shape memory alloy clamp in the embodiment of this utility model;

[0027] Figure 5 This is a top view of the shape memory alloy clamp in an embodiment of this utility model.

[0028] Explanation of reference numerals in the attached drawings: 1. Upper mold base; 2. Pad; 3. Lower mold base; 4. Pull rod; 5. Upper roller; 6. Positioning screw; 7. Fiber optic splice tube; 8. Lower roller; 9. Connecting shaft; 10. Air pressure hole; 11. Arc-shaped positioning groove; 12. Servo motor; 13. Fiber grating; 14. Grating demodulator; 15. Fiber optic cable; 16. Optical time domain reflectometer; 17. Shape memory alloy fixture. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, abutting connections, or integral connections. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this utility model, unless otherwise stated, "a plurality of" or "several" means two or more.

[0033] like Figure 1 and Figure 2As shown, this embodiment provides a bender for optical fiber splice tubes, including an upper mold base 1 and a lower mold base 3 fixed at a relative interval. The upper mold base 1 and the lower mold base 3 have matching arc-shaped positioning grooves 11 for the optical fiber splice tube 7 to pass through on their opposite surfaces. A pad 2 for absorbing and dispersing the lateral shear force on the optical fiber splice tube 7 during bending is provided in the space enclosed by the two arc-shaped positioning grooves 11. An upper roller 5 and a lower roller 8 are provided between the upper mold base 1 and the lower mold base 3. The upper roller 5 and the lower roller 8 are respectively located above and below the arc-shaped positioning grooves 11 and are in contact with the surface of the optical fiber splice tube 7. The lower roller 8 is fixedly connected to the lower mold base 3. The upper roller 5 is pressed against the lower mold base 3 and can rotate relative to the lower mold base 3. A power component is also connected to the lower mold base 3 to drive the upper roller 5 to rotate so that the optical fiber splice tube 7 can be bent. During operation, the fiber optic splice tube 7 is placed inside the bushing 2 of the bender. The upper roller 5 is driven to rotate by the control power component, applying pressure to the fiber optic splice tube 7. At the same time, the lower roller 8 supports the fiber optic splice tube 7. The bending action of the fiber optic splice tube 7 is completed through the cooperation of the upper roller 5 and the lower roller 8. During this bending process, the bushing 2 absorbs and disperses the lateral shear force on the fiber optic splice tube 7, greatly reducing the risk of fiber damage.

[0034] In a refined embodiment, the lower mold base 3 adopts a ┌-shaped structure, and the upper mold base 1 is positioned directly below the horizontal section of the lower mold base 3 and opposite to the vertical section. The upper mold base 1 and the lower mold base 3 are fixed by four positioning screws 6, and the fitting gap between the upper mold base 1 and the lower mold base 3 is ≤0.05mm. The arc-shaped positioning grooves 11 on the upper mold base 1 and the lower mold base 3 adopt a C-shaped groove structure. Preferably, the arc length of the arc-shaped positioning grooves 11 is designed to be 1 / 3 of the circumference of the outer wall of the fiber optic splice tube 7. In this way, the contact area between the upper mold base 1 and the lower mold base 3 and the fiber optic splice tube 7 only covers 1 / 3 of the fiber optic splice tube 7. During the bending process of the fiber optic splice tube 7, the fiber optic splice tube 7 undergoes partial contact bending. By replacing the overall compression with this partial contact bending, the direct pressure on the optical fiber can be effectively avoided, further reducing the risk of fiber damage.

[0035] In one specific embodiment, the pad 2 is made of two semi-circular beryllium bronze sleeves. The Shore A hardness of beryllium bronze is 30±5. The elastic deformation characteristics of beryllium bronze absorb and disperse the lateral shear force on the optical fiber splice tube 7 during bending. The inner surface curvature of the two beryllium bronze sleeves matches the outer wall curvature of the optical fiber splice tube 7. When the optical fiber splice tube 7 is placed, the two beryllium bronze sleeves hold the outer surface of the optical fiber splice tube 7.

[0036] In an optimized implementation, the tube bender is further equipped with an adjustment unit for adjusting the clamping force of the adjusting pads 2 and the fiber optic splice tubes 7; in some embodiments, this adjustment unit may adopt a pneumatic floating support structure, specifically, as shown in... Figure 2 As shown, an air pressure hole 10 is provided on the side of the lower mold base 3 facing away from the upper mold base 1. The air pressure hole 10 is connected to the arc-shaped positioning groove 11 on the lower mold base 3. The air pressure hole 10 of the lower mold base 3 is connected to an external compressed air device through an external air passage. By applying air pressure (working pressure 0.4-0.6MPa) to the air pressure hole 10 from the outside, the air inside the lower mold base 3 pushes the pad 2 to press the optical fiber splice tube 7, thereby automatically adjusting the clamping force according to the outer diameter of the optical fiber splice tube 7.

[0037] In some embodiments, the power component for driving the upper roller 5 to rotate is designed as a servo motor 12. The upper roller 5 and the lower mold base 3 are pressed together by a connecting shaft 9. The connecting shaft 9 and the servo motor 12 are connected by a coupling. The servo motor 12 drives the upper roller 5 to rotate, thereby realizing the bending action of the optical fiber splice tube 7.

[0038] Furthermore, a pull rod 4 is welded and fixed on the lower mold base 3. The pull rod 4 can be manually applied to drive the upper roller 5 to rotate, so that the optical fiber splice tube 7 can complete the bending action.

[0039] In addition, such as Figure 3 As shown, this embodiment also provides a bending and straightening system for optical fiber splice tubes, including several sets of the above-mentioned tube benders and a stress monitoring component for monitoring the strain of the bent section of the optical fiber splice tube 7. Each of the tube benders is evenly spaced along the axial direction of the optical fiber splice tube 7. The stress monitoring component includes a fiber Bragg grating 13 and a grating demodulator 14. The fiber Bragg grating 13 passes through the optical fiber splice tube 7, and its outlet end is connected to the grating demodulator 14. In this embodiment, multiple sets of tube benders are arranged in segments along the axial direction of the optical fiber splice tube 7, with each set of benders independently controlled. This allows for gradual pressure application to the optical fiber splice tube 7 segment by segment. Simultaneously, the design of the gasket 2 utilizes a multi-level stress-dispersed bending method to convert the lateral shear force borne by the optical fiber splice point into uniform axial stress. Furthermore, the stress monitoring component monitors the stress state of the optical fiber splice tube 7 in real time during the bending process, ensuring that the bending stress is within a safe threshold and significantly reducing the risk of optical fiber damage.

[0040] Specifically, in this embodiment, six sets of pipe benders are used, with the spacing between each set set set according to the formula L=(D×π) / 6 (where D is the outer diameter of the fiber optic splice tube). During the bending process, a local contact bending technique is employed, activating only the rollers of the pipe bender corresponding to the target bending area (the rollers of the other pipe benders are in a free-rotating state). The rotation of the rollers causes the fiber optic splice tube 7 to complete a single micro-bend of no more than 10° in the designated section. This process is repeated until the target bending angle is reached. Simultaneously, a fiber optic grating 13 is embedded in the fiber optic splice tube 7 to collect the maximum principal strain value of the bent section of the fiber optic splice tube 7. When the strain exceeds the threshold (ε≥0.15%), the PLC control system automatically adjusts the roller pressure until the strain falls back to the safe range.

[0041] In an optimized implementation, the outlet end of the optical fiber 15 in the optical fiber splice tube 7 is connected to an optical time domain reflectometer 16 for real-time monitoring of the insertion loss of the optical fiber 15. During the bending process, the optical time domain reflectometer 16 collects optical fiber insertion loss data once per second. If the insertion loss is detected to be >0.3dB, an alarm is immediately triggered and the tension of the tube bender is adjusted (adjustment accuracy ±0.5N) or the bending action is paused until the insertion loss is restored to ≤0.3dB. Through this active optical loss suppression operation, the transmission performance of the optical fiber 15 is guaranteed.

[0042] Furthermore, to adapt to downhole oil well scenarios and ensure the high-pressure sealing performance of the fiber optic splice tube 7, a pressure test was conducted on the fiber optic splice tube 7 in a bent state. Specifically, the end of the fiber optic splice tube 7 is equipped with a pressure testing hole. A hydraulic pump is connected to the pressure testing hole through a connector. The hydraulic pump applies pressure to the inside of the fiber optic splice tube 7 in stages. In the first stage, the pressure is increased from 0 to 10 MPa, and in the second stage, the pressure is increased from 10 MPa to 40 MPa. Each stage increases by 5 MPa, allowing the metal composite structure of the fiber optic splice tube 7 to gradually adapt to the high pressure in the curved state, avoiding instantaneous stress that could cause the splice tube seal to fail. After the fiber optic splice tube 7 is bent to the preset curvature, it is connected to the hydraulic pump and a pressure of 40 MPa is applied for 30 minutes.

[0043] After the bent fiber optic splice tube 7 arrives at the well site, during the straightening process of the fiber optic splice tube 7, based on the bending angle parameters of the splice tube 7 by the bender in the bending process mentioned above, the bender is driven to reverse the original bending trajectory, precisely driving the bender to perform equal-amount back bending compensation; and the straightness of the fiber optic splice tube 7 is monitored in real time. When the detected value is >0.05mm, the bender is dynamically adjusted for fine-tuning correction; at the same time, a progressive hydraulic loading strategy is adopted, applying pressure in stages through the hydraulic pump (first stage: 0-10MPa, rate 5MPa / s; second stage: 10-40MPa, in increments of 5MPa) to ensure that the wall of the fiber optic splice tube 7 does not undergo plastic deformation. Finally, a constant pressure of 40MPa is applied and held for 30 minutes.

[0044] In a further optimized implementation, to ensure precise bending control of the fiber optic splice tube 7, a preferred design is to monitor the three-dimensional trajectory deviation of the centerline of the fiber optic splice tube 7 in real time to guide the operation of each set of benders. Specifically, the bending and straightening system of this embodiment also includes a tooling platform for supporting each of the benders. The tooling platform is equipped with a dual-laser displacement sensor and an angle encoder for real-time calculation of the three-dimensional trajectory deviation of the centerline of the fiber optic splice tube 7. The dual-laser displacement sensor is used for displacement detection in the X / Y axis direction with an accuracy of ±1μm, and the angle encoder is used for Z-axis deflection angle detection with a resolution of 0.01°. By constructing a spatial coordinate system, the three-dimensional trajectory deviation of the centerline of the fiber optic splice tube is calculated in real time.

[0045] Preferably, the bending and straightening system of this embodiment further includes a shape memory alloy fixture 17 for bending and shaping the bent optical fiber splice tube 7; specifically, as shown in the figure... Figure 4 and Figure 5 As shown, the shape memory alloy clamp 17 is made of nickel-titanium alloy (Ni-Ti) C-shaped clamp, and the clamp surface is plated with copper (5μm thick) to enhance thermal conductivity. After bending, the fiber optic splice tube 7 is embedded in the shape memory alloy clamp 17. The shape memory effect is triggered by electric heating at 60℃ (temperature error ±2℃) to temporarily fix the curvature of the fiber optic splice tube 7 and ensure the stability of the bending shape of the fiber optic splice tube 7 during transportation. After transportation to the well site, natural cooling triggers the reverse phase transition, and the shape memory alloy clamp 17 is released for straightening. The straightness error is measured to be ≤0.1mm / m using a guide rail dial indicator, and a 40MPa pressure test is conducted in conjunction with a hydraulic pump to fully verify the geometric accuracy and structural integrity after straightening.

[0046] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this invention.

Claims

1. A tube bender for fiber optic splice tubes, characterized in that: The device includes an upper mold base and a lower mold base with a fixed relative interval. The opposing surfaces of the upper and lower mold bases are provided with matching arc-shaped positioning grooves for the fiber optic splice tube to pass through. The space enclosed by the two arc-shaped positioning grooves is provided with a pad for absorbing and dispersing the lateral shear force experienced by the fiber optic splice tube during bending. An upper roller and a lower roller are provided between the upper and lower mold bases. The upper roller and the lower roller are respectively located above and below the arc-shaped positioning grooves and are in contact with the surface of the fiber optic splice tube. The lower roller is fixedly connected to the lower mold base. The upper roller is pressed against the lower mold base and can rotate relative to the lower mold base. A power component is also connected to the lower mold base to drive the upper roller to rotate so that the fiber optic splice tube bends.

2. The pipe bender as described in claim 1, characterized in that: The power component is a servo motor. The upper roller and the lower mold base are pressed together by a connecting shaft, and the connecting shaft is connected to the servo motor by a coupling.

3. The pipe bender as described in claim 1 or 2, characterized in that: The lower mold base is equipped with a pull rod for manually rotating the upper roller.

4. The pipe bender as described in claim 1, characterized in that: The lower mold base has an air pressure hole on its side facing away from the upper mold base, and the air pressure hole is connected to the arc-shaped positioning groove on the lower mold base.

5. The pipe bender as described in claim 1, characterized in that: The pad consists of two semi-circular beryllium bronze sleeves, which hold the outer surface of the fiber optic splice tube.

6. The pipe bender as described in claim 1, characterized in that: The arc length of the arc-shaped positioning groove is 1 / 3 of the circumference of the outer wall of the fiber optic connector tube.

7. A bending straightening system for optical fiber splice tubes, characterized in that: The invention includes several sets of tube benders as described in any one of claims 1-6, and a stress monitoring component for monitoring the strain of the bent section of an optical fiber splice tube; each of the tube benders is distributed at equal intervals along the axial direction of the optical fiber splice tube, and the stress monitoring component includes a fiber optic grating and a grating demodulator, wherein the fiber optic grating passes through the optical fiber splice tube, and the exit end of the fiber optic grating is connected to the grating demodulator.

8. The bending straightening system as described in claim 7, characterized in that: The exit end of the optical fiber in the optical fiber splice tube is connected to an optical time domain reflectometer for real-time monitoring of optical fiber insertion loss.

9. The bending straightening system as described in claim 7, characterized in that: It also includes a tooling platform for supporting each of the aforementioned pipe benders, the tooling platform being equipped with a dual laser displacement sensor and an angle encoder for real-time calculation of the three-dimensional trajectory deviation of the centerline of the fiber optic splice pipe.

10. The bending straightening system as described in claim 7, characterized in that: It also includes shape memory alloy fixtures for bending and shaping bent fiber optic splice tubes.

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