Dual-Anode Nickel Plating for Precise Spark Plug Housing Coating

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Solution Overview

Problem

Existing coating methods for components like spark plug housings, such as drum coating, fail to provide high-quality coatings efficiently and quickly, especially when partial coating is required.

Innovation Solution

A coating device with an external and internal anode, a voltage generation system, and a clamping mechanism that allows for precise positioning and independent flow control, enabling rapid and high-quality coating of both inner and outer surfaces of components, particularly spark plug housings, using a nickel electrolyte.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a robotic arm is used to apply coating material to a workpiece, then labor costs are reduced and coating consistency is improved, but the cost of the coating apparatus increases and the apparatus becomes more complex

Engineering Contradiction:
Improvecoating consistencyVSAvoidapparatus complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The coating apparatus is divided into separate functional modules: a robotic arm for positioning, a coating head for material application, and a support structure. This segmentation allows each component to be optimized independently while maintaining overall system functionality, reducing the complexity burden of automation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating head incorporates self-adjusting features that automatically maintain optimal coating parameters during operation, reducing the need for complex control systems and manual intervention while preserving coating consistency.

Inventive Principle:
Principle #25Self-service

2Productivity

If a robotic arm with coating head is used, then labor costs are reduced, but the initial investment and maintenance costs increase

Engineering Contradiction:
Improvecoating efficiencyVSAvoidapparatus cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The coating head is designed with universal applicability to handle multiple coating materials and adapt to different workpiece geometries. This multi-functionality reduces the need for multiple specialized apparatuses, lowering overall investment costs while maintaining high coating efficiency across various applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The apparatus allows for easy adjustment of coating parameters such as material flow rate, application speed, and head positioning. This flexibility enables optimal performance across different production volumes and material types without requiring expensive reconfiguration or replacement of equipment.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the coating head is held stationary relative to the workpiece, then the apparatus is simpler, but the coating head cannot follow the contour of complex workpiece surfaces

Engineering Contradiction:
Improveapparatus simplicityVSAvoidcontour following accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The coating head is mounted on a robotic arm that provides dynamic positioning capabilities, allowing the coating head to move precisely along complex workpiece contours while maintaining a consistent relative position. This dynamic system achieves high contour following accuracy without requiring an overly complex fixed structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The robotic arm acts as an intermediary between the stationary base and the coating head, providing the necessary movement and positioning flexibility. This intermediary component enables contour following accuracy while keeping the base structure simple and easy to manufacture.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables rapid and high-quality coating of components, particularly spark plug housings, with the ability to control coating thickness and prevent unwanted coating on specific areas, achieving efficient and precise nickel plating.

Implementation Method 1

a coating head (140) to direct coating material onto a surface of the workpiece (102)

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Data Source

PatentEP3947784B1Coating apparatus for coating components
Publication Date: 2026.05.06 ROBERT BOSCH GMBH
  • EP3947784B1 patent drawingFigure 1

AI summary

The invention relates to a coating apparatus (1) for coating components (2), in particular for nickel plating spark-plug housings. The coating apparatus comprises: a housing (3) with an outer anode (4), which is designed to receive the component (2), an inner anode (5), which can be inserted into a through-opening (21) of the component (2), and a voltage generating device (6), wherein the voltage generating device (6) is designed to generate a first voltage between the outer anode (4) and the component (2) and also a second voltage between the inner anode (5) and the component (2), and wherein the housing (3) has an inlet (31) and an outlet (32), for introducing (71) and discharging (72) a process medium into and out of the housing (3).