Clad Tape Material for Ignition Plug Electrode Bonding

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Solution Overview

Problem

The existing methods for forming ignition plug electrodes using precious metal chips, such as laser welding, often result in voids and cracks due to unmelted regions, leading to separation and inefficiencies in production and resource usage, while also requiring excessive precious metal lengths for effective electrical properties.

Innovation Solution

A clad tape material with a precious metal layer and a base metal layer is used, where the tape is bonded to an ignition plug electrode base material using resistance welding, allowing for efficient production of electrode chips with improved handling characteristics and reduced precious metal usage by utilizing a continuous tape with a clad structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If laser welding is used to bond precious metal chip to base material, then bonding is achieved, but voids and cracks are generated leading to separation

Engineering Contradiction:
Improvebonding strengthVSAvoidbonding reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the bonding parameters by switching from laser welding to resistance welding, and by controlling the precious metal layer thickness to 1-10 μm. These parameter changes enable complete melting and bonding without voids, resolving the contradiction between bonding strength and bonding reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure with a base metal layer and a precious metal layer of controlled thickness. This composite material approach allows the base metal to provide structural integrity while the thin precious metal layer provides electrical properties, enabling reliable bonding without the defects seen in conventional approaches

Inventive Principle:
Principle #40Composite materials

2Strength

If molten zone is generated on outer peripheral surface, then bonding occurs, but precious metal chip requires excessive length

Engineering Contradiction:
Improvebonding strengthVSAvoidprecious metal usage
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The invention changes the bonding method from laser welding to resistance welding, and controls the precious metal layer thickness to 1-10 μm. These parameter changes enable effective bonding with minimal precious metal usage, resolving the contradiction between bonding strength and precious metal consumption

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The precious metal layer is pre-formed with optimal thickness (1-10 μm) before bonding. This preliminary preparation ensures that the layer is thin enough to bond completely without excessive material, while still providing the necessary electrical properties for effective bonding

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If electrode chips are handled one by one for positioning and bonding, then precise placement is achieved, but production efficiency is reduced

Engineering Contradiction:
Improveelectrode chip placement precisionVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention merges multiple electrode chips into a single strip structure with the precious metal layer continuously formed on the base metal layer. This merging allows multiple chips to be bonded simultaneously in one operation, resolving the contradiction between placement precision and production efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The continuous strip structure enables continuous bonding operation where multiple electrode positions are bonded simultaneously in one continuous process. This eliminates the need for repeated positioning and bonding operations, maintaining precision while dramatically improving production efficiency

Inventive Principle:
Principle #20Continuity of useful action

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

This approach enhances production efficiency, reduces equipment costs, and maintains the electrode's life and electrical characteristics by ensuring strong bonding and minimizing precious metal consumption.

Implementation Method 1

bonding a thin precious metal layer to a substrate including, for example, Ni or a Ni alloy by diffusive bonding under controlled bonding conditions

Methodology Applied
Scientific EffectDiffusive bonding: Diffusion Welding

Implementation Method 2

bonded to an ignition plug electrode base material by resistance welding

Methodology Applied
Scientific EffectResistance welding: Welding

Data Source

PatentEP3196995B1Tape material having clad structure for manufacturing ignition plug electrode
Publication Date: 2020.03.18 TANAKA KIKINZOKU KOGYO KK
  • EP3196995B1 patent drawingFigure 1
  • EP3196995B1 patent drawingFigure 2
  • EP3196995B1 patent drawingFigure 3

AI summary

The present invention relates to a tape material for manufacturing an ignition plug electrode, the tape material being a member for forming an electrode chip, in which a base metal layer and a precious metal layer are cladded, on a bonded region set on an electrode base material of an ignition plug, the member is in the form of a long tape in which the base metal layer being in contact with the bonded region is cladded with the precious metal layer being in contact with the base metal layer, the base metal layer has a width substantially equal to one of the longitudinal width, lateral width and diameter of the bonded region. According to the present invention, bonding between a precious metal chip and a substrate can be reliably maintained to prolong the life of an ignition plug. Accordingly, precious metals can be efficiently used to save resources.