Pipe End Forming with Elastic Expansion for One-Side Clamping

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Solution Overview

Problem

Conventional hydroforming methods require a complex and bulky structure due to the need for a sturdy sealing mechanism to contain high-pressure oil, and are inefficient in forming protrusions near the end or on bent pipes, leading to high facility costs.

Innovation Solution

A pipe end processing device using a female die with a molding surface and a male die that applies force from one end, combined with a tubular elastic body and a metal core, allowing for the formation of protrusions by introducing high-temperature fluid through the metal core, which simplifies the device and enables formation near the pipe end or on bent pipes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional hydroforming method is used to form protrusions on pipes, then protrusions can be formed, but the equipment structure becomes complex and bulky due to the need for sturdy sealing mechanisms to contain high-pressure oil

Engineering Contradiction:
Improvesealing performanceVSAvoidequipment structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the sealing mechanism from the high-pressure oil containment system by using low-pressure air instead of high-pressure oil, eliminating the need for complex sealing structures while maintaining the ability to form protrusions on pipes

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical high-pressure oil sealing system with a simpler pneumatic system using low-pressure air, substituting a complex mechanical sealing arrangement with a less demanding pneumatic approach that requires minimal sealing

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If conventional hydroforming method is used, then protrusions can be formed, but it is difficult to form protrusions close to the pipe end or on bent pipes due to the need to clamp both ends of the pipe

Engineering Contradiction:
Improveprotrusion formation capabilityVSAvoidprocessing position flexibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent removes the requirement to clamp both ends of the pipe by using a one-end clamping approach with low-pressure air inflation, enabling protrusion formation at various positions including near pipe ends and on bent pipes

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the pressure parameter from high-pressure oil to low-pressure air, which allows the pipe to be inflated and formed without requiring rigid end clamping, thereby enabling processing of bent pipes and pipes where protrusions are needed near the ends

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If conventional hydroforming method is used, then protrusions can be formed, but the facility cost becomes high due to the bulky equipment structure

Engineering Contradiction:
Improveprotrusion formation capabilityVSAvoidfacility cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the bulky high-pressure containment structure and complex sealing mechanisms by using low-pressure air, resulting in a more compact and cost-effective facility while maintaining protrusion formation capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses low-pressure air as a disposable, inexpensive medium instead of expensive high-pressure oil systems, reducing facility costs by replacing expensive equipment with simpler, more affordable components

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

Facilitates cost-effective and simplified formation of protrusions near the pipe end or on bent pipes, ensuring airtight seals and preventing disconnection by increasing friction resistance, while reducing facility size and cost.

Implementation Method 1

a tubular elastic body fitted on one end part of the metal core, the one end part protruding from the one side of the female die, the tubular elastic body being configured to be axially compressed by a movement of the metal core to radially expand by deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the metal core is formed into tubular shape so that a high-temperature fluid which is a heated stream at a temperature of 110° C to 170° C and a pressure of 0.1 to 0.6 MPa can be introduced into the pipe via the tubular metal core

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3718658B1Pipe end part processing device
Publication Date: 2025.06.25 SANOH IND CO LTD
  • EP3718658B1 patent drawingFigure 1
  • EP3718658B1 patent drawingFigure 2
  • EP3718658B1 patent drawingFigure 3~4

AI summary

An object of the present invention is to provide a pipe end processing device that allows a protrusion to be formed on a pipe by applying a force only from one end and that also serves as a device for clamping an end part of a pipe. To achieve the object, there is provided a pipe end processing device 1 including a female die 20 having a molding surface for forming a protrusion, and a male die 30 that presses a surface to be processed of a pipe against the molding surface of the female die, the female die having a through hole 21 with one side thereof being radially increased, the through hole having the molding surface 22 for forming the protrusion formed on an inner circumference on the one side of the through hole, and the male die including a metal core 31 passed through the through hole of the female die and configured to be axially moved by a drive device provided on the other side of the female die, and a tubular elastic body 32 fitted on one end part of the metal core, the one end part protruding from the one side of the female die, the tubular elastic body being configured to be axially compressed by a movement of the metal core to radially expand by deformation thereby to press the surface to be processed of the pipe against the molding surface of the female die.