Optical Fiber Preform Drilling Method for Longitudinal Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for manufacturing optical fiber preforms with holes extending in a longitudinal direction face challenges such as difficulty in procuring capillary tubes for the stack-and-draw method and limitations in hole length due to drill constraints in the drilling method, making it hard to produce large preforms economically.
Innovation Solution
The method involves forming slits on the outer surface of a cylindrical preform and using a drilling jig to create holes that extend in the longitudinal direction, allowing for unlimited hole length and reducing manufacturing costs by integrating the drilling and stretching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the drilling method is used to form holes in the preform, then arbitrary hole positions and small number of holes can be arranged, but the hole length is limited by drill length (about 500 mm at most)
Solution Approach 1:
The preform manufacturing process is segmented into two distinct stages: first forming slits on the outer surface, then forming holes that connect to these slits. This segmentation allows the hole formation to extend beyond the physical length constraints of a single drill, as the drilling jig can move along the longitudinal direction to create holes of unlimited length by connecting multiple slit openings.
Solution Approach 2:
The invention transitions from traditional through-hole drilling to a two-stage process where slits are formed on the outer surface first, then holes are formed by connecting these slits. This dimensional approach allows holes to extend along the longitudinal direction without being constrained by drill length, effectively adding a movement dimension to the hole formation process.
2Productivity
If the stack-and-draw method is used to manufacture preforms, then many holes can be arranged in constant cycle, but capillary tubes must be prepared in large quantities making procurement difficult
Solution Approach 1:
The drilling jig serves multiple functions: it forms both slits and holes, can accommodate different hole patterns and positions, and eliminates the need for specialized capillary tubes. This universal tool replaces the need for procuring large quantities of pre-prepared capillary tubes, simplifying the manufacturing process and procurement requirements.
Solution Approach 2:
Instead of using expensive and difficult-to-procure capillary tubes that must be prepared in large quantities, the invention uses a simpler drilling jig that can be reused. The process eliminates the need for specialized consumable components, reducing procurement complexity and cost.
3Productivity
If the stack-and-draw method is used, then many holes can be arranged, but unintended vacant space is formed between capillary tubes making optical fiber characteristics unstable
Solution Approach 1:
The invention replaces the mechanical assembly of capillary tubes with a direct drilling and slit-forming process on the preform. This substitution eliminates the physical gaps and vacant spaces that occur when capillary tubes are bundled together, ensuring uniform optical fiber characteristics throughout the preform structure.
Solution Approach 2:
By forming holes directly in the preform through the slit-connecting method, the invention ensures homogeneous material distribution and eliminates the heterogeneous vacant spaces that occur in stack-and-draw methods. This homogeneity stabilizes the optical fiber characteristics across the entire structure.
4Manufacturing precision
If the drilling method is used, then small number of holes at arbitrary positions can be arranged, but manufacturing large preforms is difficult and manufacturing cost increases
Solution Approach 1:
The drilling jig is designed to be movable along the longitudinal direction of the preform, allowing it to dynamically adapt to preforms of any size. This dynamic capability enables the same equipment to manufacture both small and large preforms efficiently, maintaining cost-effectiveness while preserving the flexibility to arrange holes at arbitrary positions.
Solution Approach 2:
The method performs preliminary slit formation on the outer surface before forming the actual holes. This preliminary action facilitates subsequent hole formation by providing access points, making the overall process more efficient and cost-effective for large preforms while maintaining arbitrary hole positioning capability.
Data Source
AI summary
An optical fiber preform manufacturing method includes: supporting a drilling jig in a radial direction of a preform that is cylinder-shaped; moving the drilling jig in a longitudinal direction of the preform; and forming a plurality of slits each extending in the longitudinal direction and each directed from an outer side of the preform toward a center the preform, and a plurality of holes each extending in the longitudinal direction and each connecting with an end of one of the plurality of slits in a depth direction of the one of the plurality of slits.