Connection Member Flange Forming for Flat Sealing Surfaces
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Solution Overview
Problem
Conventional methods for forming flange portions in connection structures, such as those between a turbocharger and a catalytic converter, often result in deteriorated flatness and sealing performance due to welding steps, and using seamless pipes to prevent this is costly.
Innovation Solution
A method involving blanking, burring, and folding of a seamless annular plate to form a connection member with a flange that secures high sealing performance without increasing production costs, where the folded portion is formed on the side opposite the connection surface, allowing for enhanced flatness and clamp fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a welded pipe is used to form the upstream pipe portion, then production cost is reduced, but the flatness of the connection surface deteriorates due to welding steps or bulges
Solution Approach 1:
The upstream pipe portion is divided into two separate components: a welded pipe body and a separately formed flange portion. The flange is manufactured from a flat plate through blanking and folding operations, then attached to the pipe end. This segmentation allows each component to be optimized independently - the pipe maintains its cost-effective welded construction while the flange achieves precise flatness through stamping processes.
Solution Approach 2:
The flange portion is combined with the pipe body through attachment (welding or other joining methods) to form an integrated connection assembly. This merging allows the flange to provide the necessary sealing surface while the pipe body retains its economical welded construction, resolving the contradiction between cost and precision.
2Manufacturing precision
If a seamless pipe is used to form the upstream pipe portion, then the flatness of the connection surface is maintained, but production cost increases
Solution Approach 1:
By separating the flange function from the pipe body, the solution allows the use of economical welded pipes while achieving seamless-flange-quality connection surfaces through the separately formed flange portion made from flat plate material.
Solution Approach 2:
The flange is formed from a relatively inexpensive flat plate through stamping operations, serving as a cost-effective alternative to using expensive seamless pipe material throughout the entire upstream pipe portion, while still achieving the required sealing performance.
3Ease of operation
If the folded portion is formed on the connection surface side, then clamp fastening is improved, but the flatness of the connection surface deteriorates
Solution Approach 1:
The flange design employs asymmetric folding where the folded portion is positioned on the outer peripheral side rather than on the connection surface side. This asymmetric configuration allows the clamp to engage with the folded portion for secure fastening while leaving the connection surface flat and uninterrupted, resolving the contradiction between fastening effectiveness and sealing surface quality.
Solution Approach 2:
Different regions of the flange are given different structural characteristics: the connection surface area maintains flatness for sealing, while the outer peripheral area incorporates folded portions for clamp engagement. This localized differentiation of structural properties allows each region to optimize its function without compromising the other.
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 method ensures high sealing performance and satisfactory fastening while reducing production costs by using common flat plates, preventing deformation, and improving yield.
Implementation Method 1
a blanking step of blanking a seamless annular plate from a flat plate
Implementation Method 2
a burring step of performing burring on the annular plate blanked in the blanking step to form an annular plate portion and the tube body rising from an inner periphery of the annular plate portion
Implementation Method 3
a flange forming step of forming the flange including at least one annular folded portion by folding the annular plate portion from an outer peripheral side of the annular plate portion toward an inner peripheral side of the annular plate portion
Data Source
AI summary
After an annular plate is blanked from a metal flat plate in a blanking step, an inner peripheral portion of the annular plate is deformed upward in a burring step. As a result, a hat-shaped intermediate product having an upstanding tubular portion and an annular plate portion is formed. After that, an outer peripheral portion of the annular plate portion is folded step by step toward an inner peripheral side of the annular plate portion. As a result, a folded portion composed of a first folded portion and a second folded portion is formed, whereby a connection portion having a second flange portion is formed.