Spiral Pipe Forming Without Inner Restriction for Stable Fitting
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Solution Overview
Problem
Existing pipe-forming apparatuses for spiral pipes require an inner periphery restriction body, leading to structural enlargement, increased weight, and water flow inhibition during rehabilitation of water pipes, particularly in non-circular pipes.
Innovation Solution
A pipe-forming apparatus that omits the inner periphery restriction body, using a driving part to press the strip member from the inner periphery side and a guide portion from the outer periphery side to join the strip portions, allowing for smooth propulsion and stable fitting without restricting the pipe's cross-sectional area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inner periphery restriction body is provided inside the preceding spiral pipe portion, then the cross section of the spiral pipe is restricted and fitting is stabilized, but the structure becomes enlarged and weight increases
Solution Approach 1:
The patent removes the inner periphery restriction body from the apparatus structure. Instead of using a physical restriction body, the invention uses the friction between the driving rollers and the strip member, combined with the guide portion positioning, to achieve stable fitting without the additional weight of an inner restriction structure.
Solution Approach 2:
The patent replaces the mechanical inner periphery restriction body with a friction-based driving system. The driving rollers create frictional force to press the strip member against the inner periphery, substituting the need for a rigid mechanical restriction structure with a softer friction-based mechanism.
2Manufacturing precision
If an inner periphery restriction body is provided, then the cross section is restricted from the inner periphery side, but water flow is inhibited during rehabilitation
Solution Approach 1:
The patent removes the inner periphery restriction body that was causing water flow inhibition. The cross section control function is transferred to the guide portion and driving rollers, which maintain the spiral pipe shape during formation without creating permanent flow restrictions in the finished product.
Solution Approach 2:
The patent changes the operational state of the cross section control mechanism. The driving rollers and guide portion provide temporary control during the pipe formation process, but do not remain as permanent structures that would inhibit water flow in the rehabilitated pipe.
3Reliability
If an inner periphery restriction body is provided, then fitting is stabilized through reaction force, but the apparatus structure becomes more complex
Solution Approach 1:
The patent extracts and removes the inner periphery restriction body from the apparatus. The fitting stability function is achieved through the combination of driving rollers creating frictional pressure and the guide portion positioning the strip member, eliminating the need for complex inner restriction structures.
Solution Approach 2:
The patent merges the cross section control function and the fitting stabilization function into the driving rollers and guide portion system. These components simultaneously perform multiple functions: driving the strip member forward, controlling the cross section during formation, and stabilizing the fitting process, thereby reducing overall structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus enables the formation of spiral pipes without water flow inhibition, supports non-circular cross-sections, and stabilizes fitting, reducing structural complexity and weight.
Implementation Method 1
a driving part (10) that presses the following strip portion (92) from the inner periphery side of the preceding spiral pipe portion (91) toward the fitting position (9p)
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3
AI summary
Both diameter expansion and contraction control and fitting stabilization are achieved at the same time in a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. A driving part 10 provided in an apparatus frame 30 of a pipe-forming apparatus 3N presses an unformed following strip portion 92 of the strip member 90. A reverse side guide portion 83 is engaged with a pipe end portion 91e of a preceding spiral pipe portion 91 from a reverse side. A face side guide portion 82 is engaged with the pipe end portion 91e from a face side. The face side guide portion 82 is shifted to the propulsion rear side beyond the reverse side guide portion 83. The following strip portion 92 is extruded from the driving part 10 toward an inter-guide clearance 84 between the reverse side guide portion 83 and the face side guide portion 82. The driving part 10 is position-adjustably attached to the guide portions 83, 82 or the apparatus frame 30 via a position adjustment mechanism 31a.