Variable U-Bending for Buckle-Free Reduced-Diameter Pipe Forming
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Solution Overview
Problem
The UO bending method for manufacturing pipes with large-diameter, small-diameter, and reduced diameter portions often results in buckling in the large-diameter portion due to excess material from the trapezoid-shaped reduced diameter portion, which compromises pipe strength and complicates welding.
Innovation Solution
The method involves forming a metal plate member into a U-shaped member with varying width portions, where the opening degree of the side walls in the small-diameter portion is greater than in the large-diameter portion, and includes edge bending to inhibit material flow and buckling during the O-shape bending process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the reduced diameter portion is shortened to meet design requirements, then the pipe length and productivity are improved, but buckling occurs in the large-diameter portion due to excess material flow during O-shape bending
Solution Approach 1:
The invention applies different opening degrees to different portions of the U-shaped member. Specifically, the opening degree in the small-diameter portion is made larger than in the large-diameter portion, creating local variation in geometric properties. This local quality change allows the small-diameter portion to accommodate excess material flow while preventing buckling in the large-diameter portion, thus resolving the contradiction between shortened reduced diameter portion and buckling prevention.
2Ease of manufacture
If the reduced diameter portion is shortened, then the pipe structure is simplified and manufacturing is easier, but the pipe strength deteriorates due to buckling at the reduced diameter portion
Solution Approach 1:
By creating local variation in opening degree along the axial direction of the U-shaped member, the invention strengthens the large-diameter portion where buckling would compromise pipe strength. The smaller opening degree in the large-diameter portion restricts material flow and prevents buckling, while the larger opening degree in the small-diameter portion accommodates the necessary material flow for the shortened reduced diameter portion.
3Ease of manufacture
If the reduced diameter portion is shortened, then the welding process is simplified, but welding becomes difficult due to buckling at the reduced diameter portion
Solution Approach 1:
The local variation in opening degree creates a geometry that prevents buckling in the large-diameter portion, providing a flat, stable surface for welding operations. This local geometric modification ensures that the welding process remains simple and easy to operate on the large-diameter portion, while still allowing the reduced diameter portion to be shortened as desired.
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
This configuration effectively prevents buckling in the large-diameter portion, allowing for the manufacture of pipes with shorter reduced diameter portions, enhancing strength and simplifying the welding process, particularly for instrument panel reinforcement applications.
Implementation Method 1
a U-shape bending step to bend a flat metal plate to have a U-shaped cross-section
Implementation Method 2
an O-shape bending step to bend two edges (facing areas) of the U-bent metal plate so that both facing areas face each other, thereby forming a pipe shape
Data Source
AI summary
Provided is a method of manufacturing a pipe including a large-diameter portion, a small-diameter portion, and a reduced diameter portion connecting the large-diameter portion and the small-diameter portion, the method comprising: forming a metal plate member into a U-shaped member having a U-shaped cross section; and forming the U-shaped member into a shape of the pipe. The U-shaped member includes: a curved portion facing an opening between both edges of the U-shaped cross section; and two facing side walls continued from the curved portion. An opening degree of the two facing side walls in a portion to form the small-diameter portion is larger than an opening degree of the two facing side walls in a portion to form the large-diameter portion.