Cutting device and method for fusion shrinkage and stretching of optical fiber preform

Abstract

The invention relates to a cutting device and method for fusion shrinkage and stretching of an optical fiber preform. The device comprises a stand column, an up-down lifting device and a lifting seat are arranged on the stand column, the up-down lifting device is connected with a lifting driving device, an annular guide rail is arranged on the lifting seat, a rotating seat is arranged on the annular guide rail, and the rotating seat is connected with the lifting driving device. And a laser cutter is arranged on the rotating seat. Through laser automatic annular layered cutting, a notch of the glass optical fiber preform is straight and smooth, glass burrs and microcracks are avoided, the adverse effect of cutting of other cutters on the cutting part of the preform is avoided, and the perpendicularity of the cutting surface and the preform can be ensured through synchronous downward movement of the laser and the optical fiber preform; the cutting quality is obviously improved, and the device can be used for cutting solid-core optical fiber preforms and is more suitable for cutting hollow-core optical fiber preforms; cutting is conducted in a mode synchronous with melting shrinkage stretching, stretching is not affected, the cutting speed is high, and the stretching cutting work efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to a cutting device and method for melting, shrinking, and stretching optical fiber preforms, belonging to the technical field of optical fiber preform production equipment. Background Technology

[0002] The fabrication of silica glass optical fiber preforms typically involves a shrinking and stretching process. This process requires segmenting the long, shrunken preform. Currently, the industry commonly uses manual circumferential cutting to accomplish this task. However, manual circumferential cutting presents several problems: firstly, it requires manual positioning and adjustment, making it difficult to ensure consistent cutting lengths and resulting in significant tolerances; secondly, burrs and micro-cracks are easily generated on the cut surface, damaging the optical fiber preform. Furthermore, manual circumferential cutting requires manual twisting to break the tube each time, causing stress on the entire tube and affecting its curvature. In addition, manual cutting is inefficient. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a cutting device and method for melting, shrinking and stretching optical fiber preforms, which not only has a high degree of automation and cutting efficiency, but also good cutting quality.

[0004] The cutting device technical solution adopted by the present invention to solve the above-mentioned problems is as follows: it includes a column, on which a lifting device and a lifting seat are installed. The lifting device is connected to a lifting drive device. A ring guide rail is installed on the lifting seat. A rotating seat is installed on the ring rail. A laser cutter is installed on the rotating seat.

[0005] According to the above scheme, a heater is installed above the column to preheat the cut part of the optical fiber preform.

[0006] According to the above scheme, the rotating seat is connected to the rotating drive disk, and the rotating drive disk is configured with the annular track.

[0007] According to the above scheme, a radially movable seat is installed on the rotating seat, and the radially movable seat is connected to the laser cutter.

[0008] According to the above scheme, the lifting device is a ball screw lifting device.

[0009] According to the above scheme, the rotary drive disk includes an inner turntable installed inside the annular track and an outer turntable installed outside the annular track. The inner and outer turntables are connected to each other. Gear teeth are provided on the outer circumference of the annular track. A drive pinion is installed on the outer turntable and meshes with the gear teeth on the outer circumference of the annular track. The drive pinion is connected to a motor to drive the rotary drive disk to rotate.

[0010] According to the above scheme, the radial moving seat includes a fixed seat connected to the rotating seat, a radial guide rail is provided on the fixed seat, a movable slide is arranged on the radial guide rail, the movable slide is connected to the screw and sleeve drive device, and the screw and sleeve drive device is connected to the drive motor.

[0011] The technical solution of the cutting method of the present invention is as follows: when the fused and stretched optical fiber preform reaches the predetermined length, the cutting device is started, the lifting device is adjusted to the cutting position of the optical fiber preform, and the lifting speed is the same as the stretching speed of the optical fiber preform, so that the rotating seat and the optical fiber preform move down synchronously. Then the rotating seat and the laser cutter are turned on, so that the laser cutter follows the rotating seat and rotates around the optical fiber preform at a uniform speed to perform laser circumferential cutting on the optical fiber preform. The laser cutter radially cuts the optical fiber preform to a certain depth every time it rotates around, until it cuts to the predetermined radial depth or radially breaks, thus completing the cutting task.

[0012] According to the above scheme, the cutting position of the optical fiber preform is preheated by a heater before cutting, and the preheating temperature is 80~150℃.

[0013] According to the above scheme, the laser cutter rotates at a constant angular velocity of 0.1~0.8 rad / s around the optical fiber preform following the rotating seat.

[0014] According to the above scheme, the laser cutter advances radially by 0.5~4.0mm per revolution.

[0015] According to the above scheme, the radial depth of laser cutting is 2 / 3 to 3 / 4 of the radius of the optical fiber preform.

[0016] The beneficial effects of this invention are as follows: 1. Through automatic laser ring-shaped layer cutting, the glass fiber preform has a straight and smooth cut, free of glass burrs and micro-cracks, avoiding the adverse effects of other cutting tools on the preform cutting area. By using a ball screw lifting device, the laser and fiber preform move synchronously and stably downwards, ensuring the perpendicularity of the cutting surface to the preform, significantly improving the cutting quality. This invention can cut solid fiber preforms and is more suitable for cutting hollow fiber preforms; 2. Cutting is performed synchronously with the fusion shrinking and stretching process, without affecting the stretching process, and the cutting speed is fast, effectively improving the efficiency of stretching and cutting; 3. Preheating the fiber preform cutting area can avoid the generation of micro-cracks and stress at the laser cutting point, further improving the cutting quality of the fiber preform. The device of this invention is configured with the preform fusion shrinking and stretching device and installed below the fusion shrinking and stretching device. When the fusion-shrinking and stretching fiber preform reaches the predetermined length, the cutting device is activated. This invention has a compact and reasonable structure, is easy to use, and has a high degree of automation. Attached Figure Description

[0017] Figure 1 This is a front view structural diagram of an embodiment of the present invention.

[0018] Figure 2 This is a side view of an embodiment of the present invention.

[0019] Figure 3 This is a top view of an embodiment of the present invention.

[0020] Figure 4 This is a top view of the radial moving seat in one embodiment of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0022] The system includes a column 3, a guide rail 15 mounted on the column, and a lifting device and lifting seat 5 installed on the column. The lifting seat moves up and down along the guide rail. The lifting device is a ball screw lifting device, which includes an upper support seat 12, a lower support seat 16, and a ball screw 14 installed at the upper and lower ends of the column. The ball screw is configured with a ball threaded sleeve. The upper end of the ball screw is connected to a lifting drive device, which is a lifting drive motor 2. The ball threaded sleeve is connected to the lifting seat through a connecting plate 13. A heater, a preheating furnace 1, is installed above the column for preheating the cut portion of the optical fiber preform 6. See [link to relevant documentation]. Figure 1 , Figure 2 A limit sensor 22 can be installed on one side of the column, configured to correspond with the limit plate 21 on the lifting seat, for limiting the movement of the lifting seat. The lifting seat is equipped with an annular guide rail 4, on which a rotary drive disk is mounted. A rotary seat 10 is mounted on the rotary drive disk, and the rotary seat is connected to the rotary drive disk. The rotary drive disk includes an inner turntable 20 mounted inside the annular track and an outer turntable 17 mounted outside the annular track. The inner and outer turntables are interconnected. Gear teeth are provided on the outer circumference of the annular track. A drive pinion is mounted on the outer turntable, meshing with the gear teeth on the outer circumference of the annular track. The drive pinion is connected to a motor, driving the rotary drive disk to rotate. (See also...) Figure 3 The rotary seat is equipped with a radially movable seat 8, which includes a fixed seat 19 connected to the rotary seat. A radial guide rail 24 is provided on the fixed seat, and a movable slide plate 18 is mounted on the radial guide rail. The lower part of the movable slide plate is connected to the guide rail and a screw and sleeve drive device. The screw and sleeve drive device includes a lead screw 27 and a sleeve. The lead screw is supported by a front support seat 23 and a rear support seat 25. The lead screw is connected to a drive motor 9 via a coupling 26. The sleeve is connected to the movable slide plate. The radially movable seat is connected to the laser cutter 7. (See also...) Figure 4 .

[0023] The glass fiber preform cutting method using the above-mentioned device of the present invention is as follows: The device of the present invention is configured with the preform melting and stretching device and installed below the melting and stretching device. When the melt-stretched fiber preform reaches the predetermined length, the cutting device is started. Before cutting, the cutting position of the fiber preform is preheated in a preheating furnace at a preheating temperature of 80~100℃. Then, the lifting device is adjusted to the cutting position of the fiber preform and the lifting speed is the same as the stretching speed of the fiber preform, so that the rotating seat moves down synchronously with the fiber preform. Then, the rotating seat and the laser cutter are turned on, so that the laser cutter follows the rotating seat and rotates around the fiber preform at a uniform speed. The angular velocity of the laser cutter following the rotating seat around the fiber preform is 0.2~0.8 rad / s. The laser cutter advances radially by 0.5~3.0 mm for each revolution. The optical fiber preform is laser-cut around its perimeter. The laser cutter makes radial cuts to a certain depth on each perimeter until the preform is cut to the predetermined radial depth or breaks radially, thus completing the cutting task.

[0024] Solid fiber preform: The laser cutter follows the rotating base and rotates uniformly around the fiber preform → the laser cutter advances radially and performs layered circumferential cutting → repeats until the solid core material is cut through.

[0025] Hollow fiber preform: thin-walled, nested multi-layered glass tube microstructure with a central cavity. The laser cutter follows the rotating seat and rotates uniformly around the fiber preform → input the structural parameters of each nested tube layer of the hollow fiber preform → the laser cutter advances radially according to the structural parameters of each nested tube layer → repeat until the central cavity is cut.

[0026] Cutting process requirements: cut roughness Ra≤0.8μm, no radial microcracks, no chipping on the end face, and no scratches or debris on the inner wall of the hollow preform.

[0027] Example 1: Cutting of solid fiber preforms. The preform melting and stretching speed is 600 mm / min, the target glass tube has an outer diameter of 20 mm, and a length of 1 m. The cutting device starts operating when the stretched glass tube length reaches 1 m. The laser cutter follows the rotating base and rotates uniformly around the fiber preform at an angular velocity of 0.6 rad / s. The laser cutter advances radially by 2 mm per revolution, for a total of 4 revolutions. The glass tube can be broken instantly by external force, ensuring cutting quality.

[0028] Example 2: Hollow fiber preform cutting. The preform stretching speed is 600 mm / min. The target glass tube has an outer diameter of 25 mm and contains three nested tubes. The distance between each nested tube and the outer diameter of the glass tube is set so that the laser cutter advances radially by 0.6 mm, 1 mm, and 2 mm per revolution. The target glass tube length is 1 m. When the stretched glass tube length reaches 1 m, the cutting device starts working. The laser cutter follows the rotating base and rotates uniformly around the fiber preform at an angular velocity of 0.3 rad / s. The laser cutter advances radially by the set step distance per revolution, for a total of 3 steps. The glass tube can be broken instantly by external force, ensuring the cutting quality.

Claims

1. A cutting device for shrinking and stretching optical fiber preforms, characterized in that... It includes a column, on which a lifting device and a lifting seat are installed. The lifting device is connected to a lifting drive device. The lifting seat is equipped with a ring guide rail, and a rotating seat is installed on the ring rail. A laser cutter is installed on the rotating seat.

2. The cutting device for shrinking and stretching optical fiber preforms according to claim 1, characterized in that... A heater is installed above the column to preheat the cut part of the optical fiber preform.

3. The cutting device for shrinking and stretching optical fiber preforms according to claim 1 or 2, characterized in that... The rotating seat is connected to the rotating drive disk, and the rotating drive disk is configured with the annular track.

4. The cutting device for shrinking and stretching optical fiber preforms according to claim 3, characterized in that... The rotary seat is equipped with a radially movable seat, which is connected to the laser cutter.

5. The cutting device for shrinking and stretching optical fiber preforms according to claim 1 or 2, characterized in that... The aforementioned lifting device is a ball screw lifting device.

6. The cutting device for shrinking and stretching optical fiber preforms according to claim 3, characterized in that... The rotary drive disk includes an inner turntable installed inside the annular track and an outer turntable installed outside the annular track. The inner and outer turntables are connected to each other. The annular track is provided with gear teeth on its outer circumference. A drive pinion is installed on the outer turntable and meshes with the gear teeth on the outer circumference of the annular track. The drive pinion is connected to a motor to drive the rotary drive disk to rotate.

7. The cutting device for shrinking and stretching optical fiber preforms according to claim 4, characterized in that... The radially movable seat includes a fixed seat connected to the rotating seat, a radial guide rail is provided on the fixed seat, a movable slide is arranged on the radial guide rail, the movable slide is connected to a screw and sleeve drive device, and the screw and sleeve drive device is connected to a drive motor.

8. A cutting method for the melting and stretching of optical fiber preforms, characterized in that... Using any one of the cutting devices described in claims 1-7, when the fused and stretched optical fiber preform reaches the predetermined length, the cutting device is activated, the lifting device is adjusted to the cutting position of the optical fiber preform, and the lifting speed is the same as the stretching speed of the optical fiber preform, so that the rotating seat moves down synchronously with the optical fiber preform. Then, the rotating seat and the laser cutter are turned on, so that the laser cutter follows the rotating seat and rotates around the optical fiber preform at a uniform speed to perform laser circumferential cutting on the optical fiber preform. The laser cutter radially cuts the optical fiber preform to a predetermined depth every time it rotates around, until it cuts to the predetermined radial depth or radially breaks, thus completing the cutting task.

9. The cutting method for shrinking and stretching optical fiber preforms according to claim 8, characterized in that... Before cutting, the cutting area of ​​the optical fiber preform is preheated by a heater at a temperature of 80~100℃.

10. The cutting method for shrinking and stretching optical fiber preforms according to claim 8 or 9, characterized in that... The laser cutter rotates uniformly around the optical fiber preform with a speed of 0.1~0.8 rad / s, following the rotating base.

11. The cutting method for shrinking and stretching optical fiber preforms according to claim 8 or 9, characterized in that... The laser cutter advances radially by 0.5 to 4.0 mm per revolution.

12. The cutting method for shrinking and stretching optical fiber preforms according to claim 8 or 9, characterized in that... The radial depth of laser cutting is 2 / 3 to 3 / 4 of the radius of the optical fiber preform.

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