Corrugated Thermoplastic Pipe Polygonal Reliefs

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Solution Overview

Problem

Corrugated thermoplastic pipes used in motor vehicle cooling circuits face issues with flattening and elongation due to high operating temperatures and pressures, as their rounded geometries compromise flexibility and resistance.

Innovation Solution

A fluid transfer pipe with monolayer or multilayer corrugated portions made of thermoplastic materials, featuring radial reliefs with polygonal contours and convex bulbs, which are designed to minimize axial elongation and facilitate demolding, using extrusion-blow molding for production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If rounded geometries are used for the contours of annular reliefs in corrugated thermoplastic pipes, then flexibility of the pipe is improved, but axial elongation of the reliefs occurs due to high operating temperatures and pressures

Engineering Contradiction:
ImproveflexibilityVSAvoiddimensional stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The relief contours transition from rounded (axisymmetric) geometries to asymmetric polygonal geometries with straight sections and rounded corners. This asymmetry allows the reliefs to maintain flexibility through the rounded corners while the straight sections prevent axial elongation under thermal and pressure loads, resolving the contradiction between flexibility and dimensional stability.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention changes the geometric parameters of the relief contours by introducing straight sections with specific lengths and rounded corners with specific radii. By optimizing these parameters, the pipe achieves both flexibility (through adequate corner rounding) and resistance to axial elongation (through sufficient straight section length), directly addressing the technical contradiction.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If polygonal contours with straight sections are used for the reliefs, then resistance to axial elongation is improved, but flexibility may be compromised

Engineering Contradiction:
Improveresistance to elongationVSAvoidflexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The polygonal contour design with straight sections and rounded corners creates an asymmetric geometry that optimizes both flexibility and elongation resistance. The rounded corners provide the necessary flexibility for pipe deflection, while the straight sections between corners prevent axial elongation, resolving the contradiction between these two properties.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different portions of the relief contour are given different geometric qualities: rounded corners for flexibility and straight sections for elongation resistance. This local differentiation of geometric properties allows the single contour design to simultaneously achieve both flexibility and resistance to axial elongation.

Inventive Principle:
Principle #3Local quality

3Reliability

If complex relief geometries are used to achieve both flexibility and elongation resistance, then performance is improved, but manufacturing complexity increases

Engineering Contradiction:
ImproveperformanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The relief contour is segmented into distinct straight sections and rounded corner sections, each serving a specific function. This segmentation allows for optimized performance while maintaining manufacturability, as each segment can be independently designed and controlled during the molding process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By defining specific geometric parameters (straight section length, corner radius, polygon side count), the invention transforms a complex performance requirement into controllable manufacturing parameters. This enables the complex geometry to be manufactured using standard extrusion-blow molding processes with precise parameter control.

Inventive Principle:
Principle #35Parameter changes

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 pipe achieves a balance between flexibility and resistance to elongation, ensuring dimensional stability and improved resistance to fluid pressure, as demonstrated by tests under simulated conditions.

Implementation Method 1

using extrusion-blow molding for production

Methodology Applied
Scientific EffectExtrusion-blow molding:

Data Source

PatentEP2428716B1Fluid transfer pipe with corrugated portion(s) and method for manufacturing same
Publication Date: 2016.06.22 HUTCHINSON SRL
  • EP2428716B1 patent drawingFigure 1~9
  • EP2428716B1 patent drawingFigure 10~11
  • EP2428716B1 patent drawingFigure 12~13

AI summary

The present invention relates to a fluid transfer pipe, particularly for the pressurization of a cooling circuit in a motor vehicle, and its manufacturing process. This pipe comprises at least one corrugated, bendable portion (10) made of at least one thermoplastic material and comprising a succession of axially spaced radial reliefs forming hollows between them, each relief having two frontal zones joined together by an intermediate zone, the frontal zones of each relief each having the same overall polygonal contour (15) defining at least three straight sections forming flats (20) for this relief and connected to each other by rounded sections forming bulbs (19) for this relief, and the contours of the successive reliefs being adapted to allow the demolding of the corrugated portion from two semi-cylindrical shells of a mold along a single axial demolding plane.According to the invention, at the rounded sections of each relief, the two frontal zones meet in the intermediate zone, forming for each relief n (n ≥ 3) discontinuous convex bulbs in the circumferential and axial directions.