Wiring Harness Ink Usage Reduction via Localized Marking

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Solution Overview

Problem

Conventional wiring harness manufacturing methods require excessive ink usage for color-based identification of electric wires, leading to increased costs and inefficiencies, especially when both mechanically and manually incorporated wires are involved.

Innovation Solution

The method involves printing circuit identifiers on the intermediate portions of electric wires using compact representations like characters, dots, and symbols, reserving colored markers only for manually incorporated wires and using inexpensive ink for these markers, which are placed at regular intervals to ensure discernibility and readability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If coloring features are applied to all electric wires for identification, then wire discernibility is improved, but ink usage increases considerably

Engineering Contradiction:
Improvewire discernibilityVSAvoidink usage
Core Design Contradiction:
Loss of informationVSLoss of substance

Solution Approach 1:

The patent applies different identification methods to different parts of the wiring system: circuit identifiers (printed characters/dots/symbols) are placed at intermediate portions of all wires, while colored markers are applied only at end portions of manually-incorporated wires. This localized differentiation reduces overall ink usage while maintaining comprehensive wire identification.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses printed circuit identifiers (characters, dots, symbols) as a compact representation system that conveys connection destination information more efficiently than traditional colored markers. This copying approach allows multiple wires to be distinguished using the same ink color, significantly reducing total ink consumption.

Inventive Principle:
Principle #26Copying

2Reliability

If expensive ink is used to ensure colorability and prevent ink from coming off, then wire identification reliability is improved, but manufacturing costs increase

Engineering Contradiction:
Improveink fastnessVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies different ink types to different locations: inexpensive ink is used for circuit identifiers at intermediate portions where fastness is less critical, while expensive fastness ink is used only for colored markers at end portions of manually-incorporated wires where identification reliability is most important. This selective application reduces overall manufacturing costs while maintaining necessary reliability.

Inventive Principle:
Principle #3Local quality

3Loss of information

If colored markers are applied to all wires including mechanically-incorporated wires, then complete wire identification is improved, but ink usage increases unnecessarily

Engineering Contradiction:
Improvewire identification completenessVSAvoidink usage
Core Design Contradiction:
Loss of informationVSLoss of substance

Solution Approach 1:

The patent differentiates between manually-incorporated wires (which require colored markers at end portions for operator identification) and mechanically-incorporated wires (which rely solely on printed circuit identifiers at intermediate portions). This localized application of colored markers eliminates unnecessary ink usage on mechanically-incorporated wires while maintaining complete identification capability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2543047B1Wiring harness and manufacturing method thereof
Publication Date: 2019.07.24 YAZAKI CORP
  • EP2543047B1 patent drawingFigure 1A~1B
  • EP2543047B1 patent drawingFigure 2A~2E
  • EP2543047B1 patent drawingFigure 3

AI summary

There is provided an electric wire 1 comprising an electrically-conductive conductor portion and an insulating cover portion 11 covering the conductor portion. A colored marker 13 is provided on an end portion of the cover portion 11. The colored marker 13 indicates that the electric wire is a manually-incorporated wire. A circuit identifier 12 is provided on an intermediate portion of the cover portion 11. The circuit identifier 12 is made by printing or provided in the form of a mark and indicative of a connection destination of the electric wire 1. The colored marker in the end portion is made by an ink inferior to that of the circuit identifier on the intermediate portion in at least one property selected from among adhesiveness, weatherability, heat resistance, and chemical resistance.