Metal Pipe Flange Forming with Local Crush Zones for Welding

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Solution Overview

Problem

In existing forming devices, the flange portion of metal pipes is either crushed too much, preventing coating liquid entry, or expanded too much, reducing weldability when joined with other members.

Innovation Solution

The forming device uses dies with protrusion mechanisms on the flange forming surfaces to create a secure welding area while allowing coating liquid entry by forming gaps in the flange portion, ensuring both weldability and coating liquid access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the flange portion is completely crushed to improve weldability, then welding strength is improved, but coating liquid cannot enter the inside of the flange portion

Engineering Contradiction:
Improvewelding strengthVSAvoidcoating liquid entry
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The invention applies local quality by creating a protrusion portion at a specific location on the flange forming surface. This protrusion creates a localized crushed region that serves as a welding area with high density and strength, while the surrounding areas maintain gaps that allow coating liquid entry. The protrusion portion is positioned at the center of the flange forming surface, creating a differentiated structure where the center region is optimized for welding and the peripheral regions are optimized for coating access.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If a space inside the flange portion is enlarged to allow coating liquid entry, then coating liquid can easily enter, but a large gap is generated and weldability decreases

Engineering Contradiction:
Improvecoating liquid entryVSAvoidweldability
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The protrusion portion creates a localized region of intense crushing that maintains welding strength while allowing gaps to exist in other regions. The crushed region around the protrusion portion provides the dense structure needed for welding, while the gaps between the protrusion and the flange outer peripheral surface provide pathways for coating liquid entry.

Inventive Principle:
Principle #3Local quality

3Reliability

If the flange portion is crushed firmly to improve welding quality, then welding strength is improved, but the entire flange portion becomes dense and prevents coating liquid penetration

Engineering Contradiction:
Improvewelding qualityVSAvoidcoating liquid penetration barrier
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention creates a localized crushed region rather than uniformly crushing the entire flange portion. The protrusion portion and its surrounding area form a dense zone suitable for welding, while the gaps between the protrusion and the flange outer peripheral surface remain open to allow coating liquid penetration.

Inventive Principle:
Principle #3Local quality

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 solution allows easy entry of coating liquid into the flange portion while maintaining weldability, enhancing the metal pipe's rust prevention and joining capabilities.

Implementation Method 1

a gas is supplied into a heated metal pipe material so as to expand the metal pipe material

Methodology Applied
Scientific EffectGas pressure expansion: Pressure Increase

Implementation Method 2

a gas is supplied into a heated metal pipe material

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP3597323B1Molding device and molding method
Publication Date: 2022.08.03 SUMITOMO HEAVY IND LTD
  • EP3597323B1 patent drawingFigure 1
  • EP3597323B1 patent drawingFigure 2A~2B
  • EP3597323B1 patent drawingFigure 3A~3C

AI summary

A forming device of forming a metal pipe having a pipe portion includes a first die and a second die which are paired with each other, and constitute a first cavity portion configured to form the pipe portion and a second cavity portion which communicates with the first cavity portion and is configured to form a flange portion of the metal pipe when the first and second dies are closed, a drive mechanism configured to move at least one of the first die and the second die in a direction in which the dies are joined to each other, and a gas supply unit configured to supply a gas into a metal pipe material which is held between the first die and the second die and is heated, in which each of the first die and the second die has flange forming surfaces which face each other and constitute the second cavity portion, and a protrusion portion, which protrudes from one flange forming surface to the other flange forming surface, is formed on at least one of the flange forming surfaces of the first die and the second die.