Cylinder Bore Surface Processing for Coating Adhesion

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Solution Overview

Problem

The internal diameter of cylindrical bores with roughened surfaces cannot be accurately measured before thermally sprayed coating deposition, leading to inconsistent coating thickness and adhesion issues.

Innovation Solution

A method and system that form a smoother internal diameter measurement surface section within the cylindrical bore, allowing for precise measurement and adjustment of spray conditions for the thermally sprayed coating, ensuring proper thickness and adhesion by controlling the tool feed speed and spray gun movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the internal surface of the cylindrical bore is roughened to improve coating adhesion, then coating adhesion is improved, but internal diameter measurement precision deteriorates

Engineering Contradiction:
Improvecoating adhesionVSAvoidinternal diameter measurement precision
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

The internal surface of the cylindrical bore is divided into two distinct sections: a rough surface section for coating deposition and a smooth measurement surface section for accurate diameter measurement. This segmentation allows the rough surface to provide anchoring profiles for coating adhesion while the smooth section enables precise measurement without interference from surface irregularities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different surface qualities are applied to different locations within the cylindrical bore. The rough surface section has high surface area and anchoring profiles optimized for coating adhesion, while the smooth measurement surface section has low surface roughness optimized for measurement accuracy. Each section serves its specific function with appropriate local properties.

Inventive Principle:
Principle #3Local quality

2Strength

If the internal surface is roughened before coating deposition, then coating adhesion is improved, but coating thickness uniformity deteriorates

Engineering Contradiction:
Improvecoating adhesionVSAvoidcoating thickness uniformity
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The rough surface section is prepared in advance with controlled anchoring profiles before coating deposition. By pre-forming the rough surface with specific geometry and characteristics, the coating application process can be optimized to achieve uniform thickness while maintaining strong adhesion through the predetermined surface structure.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If measurement is performed on the rough surface, then measurement process is simplified, but measurement accuracy deteriorates

Engineering Contradiction:
Improvemeasurement process simplicityVSAvoidinternal diameter measurement accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The measurement function is separated from the coating deposition function by creating a dedicated smooth measurement surface section. This segmentation allows measurement to be performed on a surface specifically optimized for accuracy, while the rough surface section handles coating adhesion requirements.

Inventive Principle:
Principle #1Segmentation

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 accurate measurement and uniform thermally sprayed coating thickness, improving adhesion and reducing waste by ensuring the coating is only formed if measurement criteria are met, thus enhancing the quality and efficiency of the surface processing.

Implementation Method 1

a coating is formed on the internal surface of the cylinder bore using a thermal spray gun configured to spray molten coating material

Methodology Applied
Scientific EffectThermal spraying: Plasma Spray

Implementation Method 2

the forming of the rough surface section and the forming of the internal diameter measurement surface section are performed by cutting with a tool while both rotating and moved axially moving the tool

Methodology Applied
Scientific EffectMechanical cutting: Abrasion

Data Source

PatentEP1832381B1Surface Processing
Publication Date: 2015.10.28 NISSAN MOTOR CO LTD
  • EP1832381B1 patent drawingFigure 1
  • EP1832381B1 patent drawingFigure 2
  • EP1832381B1 patent drawingFigure 3(a)~3(f)

AI summary

Before a thermally sprayed coating is deposited onto a cylindrical internal surface of a cylinder bore 3a rough surface 13 is formed to increase the adhesion of the thermally sprayed coating. After forming the rough surface is completed, an internal diameter measurement surface that is smoother than the rough surface is formed on an axial end section of the internal cylindrical surface. The internal diameter of the cylinder bore is measured at the internal diameter measurement surface with an internal diameter measuring instrument. An appropriate thickness for the thermally sprayed coating is determined based on the measurement result.