Spiral Pipe Forming Without Inner Limiters for Variable Diameter
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Solution Overview
Problem
Conventional pipe-making apparatuses increase in size due to annular and radial inner periphery limiters, and struggle to adjust for changes in inner diameter or cross-sectional configuration of existing pipes.
Innovation Solution
A pipe-making apparatus with a non-inner-periphery-limited structure that uses a fitting height adjuster to variably adjust the fitting position of the strip member along the machine height and pipe inside-outside directions, allowing for adjustable diameter and perimeter without an inner periphery limiter, enabling the production of spiral pipes with enlarged or reduced diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an annular inner periphery limiter is used to prevent reduction in diameter, then the diameter stability is improved, but the apparatus size increases
Solution Approach 1:
The invention removes the annular inner periphery limiter from the pipe-making apparatus, replacing it with a system that uses the outer periphery limiter and control rollers to indirectly control the inner periphery of the spiral pipe through the strip member's winding process, thereby reducing apparatus size while maintaining diameter stability
Solution Approach 2:
The invention introduces control rollers as intermediary elements that press against the strip member during winding, indirectly controlling the inner periphery of the spiral pipe without requiring direct contact with the pipe's inner surface, thus avoiding the need for a large annular limiter
2Manufacturing precision
If an annular inner periphery limiter is used to limit cross-section, then the cross-sectional shape control is improved, but the adaptability to change in inner diameter decreases
Solution Approach 1:
The invention replaces the fixed annular inner periphery limiter with dynamic control rollers that can adjust their position and pressing force, allowing the apparatus to adapt to different inner diameters and cross-sectional shapes of the existing pipe being rehabilitated
Solution Approach 2:
The control rollers serve multiple functions: they guide the strip member, control the winding tension, and indirectly shape the inner periphery of the spiral pipe, making the apparatus universally applicable to various pipe configurations without requiring dedicated limiters for each diameter
3Manufacturing precision
If radial support arms with guide rollers are used to press against inner peripheral surface, then the diameter control is improved, but the device complexity increases
Solution Approach 1:
The invention divides the diameter control function into multiple discrete control rollers positioned at different locations, each independently pressing against the strip member at specific points, rather than using a continuous annular limiter, simplifying the overall device structure
Solution Approach 2:
The control rollers act as intermediary elements between the winding mechanism and the spiral pipe's inner periphery, controlling diameter through the strip member's tension and positioning rather than direct mechanical constraint, thereby reducing device complexity
Data Source
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AI summary
The present invention provides a pipe-making apparatus and a pipe-making method capable of making a spiral pipe variably adjusting a diameter or a perimeter of the pipe without an inner periphery limiter. The pipe-making apparatus 3 has a drive roller 11 disposed on a head portion of an apparatus frame 3f in a machine height direction HD, a pipe end guide 21 disposed on a basal portion of the apparatus frame 3f in the machine height direction HD and a fitting height adjuster. The drive roller 11 obliquely pushes an unformed following strip portion 92 following a preceding pipe portion 91 in the strip member 90 to a fitting position 9q on an extending end portion 91e of the preceding pipe portion 91. The pipe end guide 21 guides the apparatus frame 3f along the extending end portion 91e. The fitting height adjuster has a pipe end engagement portion 22 and a height adjusting mechanism that adjusts a position of the pipe end engagement portion 22 with respect to the drive roller 11 in the machine height direction HD.