Cylindrical Engine Bore Surface Profiling for Coating Adhesion

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Solution Overview

Problem

Existing surface roughening techniques for automotive engine bores fail to enhance the adhesion and bonding of metallic coatings effectively, leading to inadequate wear resistance and strength.

Innovation Solution

A process involving cutting tools with specific axial rows of cutting elements forms annular grooves and pockets in the engine bore surfaces, combined with a swiping tool to deform peaks, creating a profile that improves the adhesion of thermal spray coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional surface roughening techniques are used, then the inner surface is prepared for coating, but the adhesion and bonding of metallic coatings are insufficient

Engineering Contradiction:

Improveadhesion and bonding of metallic coatingsVSAvoidsurface profile quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention applies different surface treatments to different zones of the bore inner surface. The first zone (axial travel area) receives a profile with peaks and valleys optimized for coating adhesion, while the second zone (above axial travel area) has a different profile configuration. This local differentiation ensures optimal adhesion where needed while maintaining functional requirements in different regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The bore inner surface is divided into multiple axial zones with distinct profile characteristics. The first zone contains a first plurality of peaks and valleys, while the second zone contains a second plurality of peaks and valleys with different dimensions. This segmentation allows each zone to be optimized for its specific functional requirements, improving overall coating adhesion.

Inventive Principle:

Principle #1Segmentation

2Strength

If complex surface profiling is applied to enhance coating adhesion, then wear resistance improves, but manufacturing complexity increases

Engineering Contradiction:

Improvewear resistanceVSAvoidsurface profiling complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The invention varies the parameters of the surface profile (peak height, valley depth, spacing) between different axial zones to optimize wear resistance and coating adhesion. By controlling the dimensional parameters of peaks and valleys in different zones, the process achieves enhanced wear resistance without requiring overly complex manufacturing equipment.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The surface profile is created during the boring operation itself, before the metallic coating is applied. This preliminary action of creating the peaks and valleys profile during boring prepares the surface for optimal coating adhesion, eliminating the need for separate complex profiling operations after coating application.

Inventive Principle:

Principle #10Preliminary action

3Strength

If thermal spray coating is applied to roughened surfaces, then wear resistance increases, but coating cycle time and material consumption increase

Engineering Contradiction:

Improvewear resistanceVSAvoidcoating cycle time

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The invention creates a surface profile with specific peak and valley dimensions that optimizes thermal spray coating deposition. The controlled valley depths and peak heights ensure uniform coating thickness and reduced material consumption, while the pre-formed profile reduces the actual coating time required to achieve the desired wear resistance.

Inventive Principle:

Principle #3Local quality

4Strength

If metallic coating is applied to enhance wear resistance, then strength improves, but overspray and material consumption increase

Engineering Contradiction:

Improvewear resistanceVSAvoidoverspray and material consumption

Core Design Contradiction:

StrengthVSLoss of substance

Solution Approach 1:

By optimizing the dimensional parameters of the surface profile (peak height, valley depth, spacing patterns), the invention creates a surface that captures and retains thermal spray material more efficiently. This reduces overspray loss and minimizes the total material consumption required to achieve the target wear resistance level.

Inventive Principle:

Principle #35Parameter changes

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

The process enhances the strength and wear resistance of the engine bore surfaces by improving the adhesion of metallic coatings, reducing coating cycle time, material consumption, and overspray, while maintaining robustness across varying bore diameters.

Implementation Method 1

cutting tools with specific axial rows of cutting elements forms annular grooves and pockets in the engine bore surfaces

Methodology Applied

Scientific EffectMechanical cutting:

Implementation Method 2

combined with a swiping tool to deform peaks, creating a profile that improves the adhesion of thermal spray coatings

Methodology Applied

Scientific EffectMechanical deformation: Deformation

Implementation Method 3

improving the adhesion of thermal spray coatings

Methodology Applied

Scientific EffectThermal spray deposition:

Data Source

PatentUS10221806B2Cylindrical engine bore

Publication Date: 2019.03.05 FORD GLOBAL TECH LLC

AI summary

A cylinder bore including an inner surface including an axial travel area and an axial non-travel area including two discontinuous axial widths of the cylindrical bore and the axial travel area extending therebetween. A nominal diameter of the axial travel area is greater than that of the axial non-travel area. A plurality of annular grooves is formed in the two discontinuous axial widths of the cylindrical bore.