Spark Plug Electrode Welding Eccentric Error Correction

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Solution Overview

Problem

The existing methods for manufacturing spark plug electrodes face challenges in achieving high coaxial accuracy between the first and second electrode members due to positional deviations during the welding process, leading to inefficiencies and potential defects such as scratches on the end surfaces.

Innovation Solution

A method that involves detecting and correcting the eccentric error of the first electrode member before supplying the second electrode member, ensuring accurate alignment and temporary welding to improve the coaxiality and reduce manufacturing defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the first electrode member is held by a chuck during welding, then the welding process can be performed efficiently, but positional deviation (eccentric error) occurs between the actual center axis of the first electrode member and the chuck's axis, reducing manufacturing precision

Engineering Contradiction:
Improvewelding efficiencyVSAvoidcoaxial accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by detecting the eccentric error of the first electrode member before the welding process begins, and correcting this positional deviation in advance. This ensures that when welding occurs, the first and second electrode members are already properly aligned, eliminating the need for post-welding adjustments and preventing defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using a detection mechanism to measure the actual position of the first electrode member's center axis relative to the chuck's axis, then using this information to correct the positional deviation. This closed-loop control ensures high coaxial accuracy is achieved despite the initial gripping by the chuck.

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If the second electrode member is supplied and positioned on the first electrode member without pre-correction, then the manufacturing process is simpler, but defects such as scratches on end surfaces occur due to misalignment

Engineering Contradiction:
Improveprocess simplicityVSAvoiddefect-free production
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent performs the eccentric error detection and correction of the first electrode member before the second electrode member is supplied and positioned. This preliminary correction ensures proper alignment is established beforehand, preventing scratches and misalignment defects during the subsequent positioning and welding operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies preliminary anti-action by correcting the positional deviation of the first electrode member in advance, which prevents the harmful effect of misalignment from occurring during the welding process. This proactive correction eliminates the root cause of potential defects before they can manifest.

Inventive Principle:
Principle #9Preliminary anti-action

3Loss of time

If the actual center axis of the first electrode member is not aligned with the chuck's axis, then setup is faster, but the coaxiality between first and second electrode members deteriorates

Engineering Contradiction:
Improvesetup timeVSAvoidcoaxiality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent performs quick eccentric error detection and correction as a preliminary step before welding begins. This rapid correction process minimizes the additional setup time required while ensuring high coaxiality is achieved, making the alignment process both fast and precise.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual alignment procedures with an automated detection and correction system that uses sensors or vision systems to measure eccentric error and automatically adjusts the first electrode member's position, significantly improving both speed and precision of alignment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables the production of spark plug electrodes with high coaxial accuracy, reducing the occurrence of defects and enhancing manufacturing efficiency by aligning the actual center axis of the first electrode member with the chuck's axis, ensuring precise welding and improved spark plug performance.

Implementation Method 1

a laser welding step of welding outer circumferential edges of the end surfaces through which the first electrode member and the second electrode member are in contact with each other

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP2621034B1Method of manufacturing electrode complex for forming electrode of spark-plug, and method of manufacturing spark plug
Publication Date: 2018.05.02 NITERRA CO LTD
  • EP2621034B1 patent drawingFigure 1
  • EP2621034B1 patent drawingFigure 2
  • EP2621034B1 patent drawingFigure 3

AI summary

[Objective] To efficiently weld a second tip, which is a noble metal tip, to a first tip with high accuracy. [Means for Solution] A manufacturing apparatus has a plurality of chuck units (110), each including a chuck (81) for holding a first tip (11), a chuck position adjustment means (90) capable of adjusting the position of a reference center axis (C1) of the chuck (81), and a base (120) which supports the chuck position adjustment means (90). Each of the bases (120) has a shaft (92) coaxial with the reference center axis (C1) of the chuck (81). The bases (120) are rotatably disposed at equal intervals on an imaginary circle of a rotary circular table (101) via the respective shafts (92). The chuck (81) is caused to hold the first tip (11); the position of an actual center axis (C2) of the first tip (11) is measured by image processing, thereby detecting an eccentric error relative to the shaft (92); the chuck position adjustment means (90) is driven for correcting the position of the center axis (C2) of the first tip (11) so as to align the position of the center axis (C2) with the position of the shaft (92), and then a second tip is disposed; and while the chuck unit (110) is rotated about the shaft (92), the outer circumferential edges of the joining end surfaces of the first and second tips are laser-welded.