Corrugated Wire Harness Tube with Variable Pitch Bending

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Solution Overview

Problem

Conventional wire harnesses with corrugated tubes face difficulties in smooth bending at positions where bending stress is applied, as the flexible corrugated tubes are not always bent smoothly and can lead to whitening and inadequate routing regulation.

Innovation Solution

A wire harness design featuring a corrugated tubular outer cover with alternating high- and low-flexibility sections, where the intervals between concave and convex portions are varied to allow smooth bending at high-stress areas while preventing excessive bending, and a rigid straight tube portion for improved routing regulation without a protector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flexible corrugated tube is used as the outer cover, then the wire harness can be bent, but it does not bend smoothly at positions where bending stress is easily applied

Engineering Contradiction:
Improvebending capabilityVSAvoidbending smoothness
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The outer cover is designed with different corrugation intervals in different sections: a first section with a first interval and a second section with a second interval that is smaller than the first interval. This local variation in corrugation density allows the wire harness to bend smoothly at positions prone to bending stress while maintaining structural integrity elsewhere.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The corrugation interval parameter is changed along the length of the outer cover to optimize bending performance. By reducing the corrugation interval in the second section, the outer cover achieves smoother bending characteristics at critical locations without sacrificing the flexibility provided by the corrugated structure.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the corrugated tube is made flexible to allow bending, then routing regulation becomes difficult

Engineering Contradiction:
Improvebending flexibilityVSAvoidrouting regulation
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The outer cover combines sections with different properties: the first section has larger corrugation intervals providing flexibility, while the second section has smaller corrugation intervals providing enhanced routing regulation. This local differentiation allows the wire harness to be bent where needed while maintaining stable routing in critical areas.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If constant corrugation intervals are used, then manufacturing is simplified, but smooth bending at high-stress positions is compromised

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbending smoothness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

Rather than using uniform corrugation intervals throughout, the invention applies different intervals locally: a first interval in the first section and a smaller second interval in the second section. This localized variation optimizes bending smoothness at high-stress positions while maintaining reasonable manufacturing complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2922159B1Wire harness
Publication Date: 2018.04.04 YAZAKI CORP
  • EP2922159B1 patent drawingFigure 1
  • EP2922159B1 patent drawingFigure 2
  • EP2922159B1 patent drawingFigure 3

AI summary

An outer cover 16 includes a flexible tube portion 24 having flexibility and an inflexible tube portion 25. The flexible tube portion 24 has a corrugated tubular shape in which concave portions 26 and convex portions 27 both extending in a circumferential direction are alternately formed side by side in an axial direction and in which intervals of the adjacent concave portions 26 or intervals between the adjacent convex portions 27 are partially changed.