Wire Harness Exterior Member Segmentation for Path Regulation

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Solution Overview

Problem

Existing wire harness designs for high-voltage applications, such as hybrid and electric vehicles, face challenges in path regulation and moldability, particularly in incorporating a protector that balances flexibility and rigidity while ensuring effective protection and easy manufacturing.

Innovation Solution

A wire harness featuring a resin exterior member with a combination of flexible and inflexible tube parts, where the inflexible tube parts have protruding elements for improved moldability and reduced cooling time during manufacturing, and recessed areas to prevent conductive path entrapment, allowing for efficient path regulation and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a straight tube having rigidity is employed to regulate the path, then path regulation effectiveness is improved, but moldability deteriorates

Engineering Contradiction:
Improvepath regulation effectivenessVSAvoidmoldability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The tube is segmented into multiple sections along its axial direction, with each section having different flexibility characteristics. The first section has higher flexibility while the second section has lower flexibility, allowing the tube to provide path regulation in the second section while maintaining moldability through the segmented structure that enables differential cooling and contraction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the tube are given different local properties - the first section maintains higher flexibility for bending areas, while the second section has lower flexibility for path regulation areas. This local differentiation allows each section to fulfill its specific function while the overall structure remains manufacturable.

Inventive Principle:
Principle #3Local quality

2Reliability

If a complex tube structure with both flexible and rigid parts is created to regulate path, then path regulation is improved, but cooling time during molding increases

Engineering Contradiction:
Improvepath regulationVSAvoidcooling time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The tube is divided into multiple sections that can be cooled independently. Each section has its own cooling characteristics, allowing the molding process to cool different parts at different rates. This segmentation enables the complex structure to be manufactured efficiently without excessive cooling time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flexibility parameter is changed along the axial direction of the tube, creating sections with different flexibility values. This parameter variation allows the tube to provide path regulation where needed while maintaining manufacturability and controlling cooling time through the differential properties of each section.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the tube wall thickness is increased to improve rigidity for path regulation, then path regulation effectiveness is improved, but uniformity of thickness and ease of insertion deteriorate

Engineering Contradiction:
Improvepath regulation effectivenessVSAvoidease of insertion
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The tube is segmented into sections with different flexibility characteristics. The second section has lower flexibility and provides path regulation with sufficient rigidity, while the first section has higher flexibility and maintains uniform thickness for easy insertion. This segmentation allows the tube to provide rigidity where needed without compromising insertion ease.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the tube have different local quality characteristics - the first section maintains higher flexibility and uniform thickness for easy insertion, while the second section has lower flexibility for effective path regulation. This local differentiation ensures that rigidity is provided only where necessary for path regulation.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2889975B1Wire harness and manufacturing method for exterior member
Publication Date: 2019.02.27 YAZAKI CORP
  • EP2889975B1 patent drawingFigure 1
  • EP2889975B1 patent drawingFigure 2
  • EP2889975B1 patent drawingFigure 3(a)~3(c)

AI summary

An exterior member 16 includes a flexible tube part 27 having flexibility and an inflexible tube part 28 having flexibility lower than that of the flexible tube part 27. The inflexible tube part 28 has a plurality of protruding parts 30 formed to protrude from an outer surface 25 thereof. The protruding parts 30 are formed so as to extend in a circumferential direction of the outer surface 25 and arranged at intervals in an axial direction of a tube of the exterior member 16.