Pipe Connecting Device Screw Element Coating

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Solution Overview

Problem

Existing pipe connecting devices, particularly for automotive pipes, experience unwanted loosening or release due to torsion and vibrations, which is not adequately addressed by current coatings in terms of abrasion and corrosion resistance.

Innovation Solution

A pipe connecting device with a screw element featuring a first coating with a higher friction coefficient on threaded areas and a second coating with a lower friction coefficient on thread-free contact surfaces, optimized to prevent torsional forces and enhance corrosion resistance, where the first coating covers the entire screw element and the second coating is applied selectively to thread-free surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high friction coating is applied to prevent loosening, then screw connection stability is improved, but assembly difficulty increases

Engineering Contradiction:
Improvescrew connection stabilityVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

High friction coating is applied only to the threaded portions where it is needed for preventing loosening, while bearing surfaces maintain lower friction characteristics for easier assembly. This localized application resolves the contradiction by applying friction enhancement only where mechanically necessary.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the entire screw fitting is coated with uniform thickness, then manufacturing simplicity is improved, but functional performance is compromised

Engineering Contradiction:
Improvecoating application simplicityVSAvoidoverall performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The coating process is segmented into distinct steps for different regions. The patent specifies different coating types and thicknesses for threaded portions versus bearing surfaces, optimizing each area's performance while maintaining manufacturability through established coating processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different coating specifications are applied to different functional areas. The threaded portions receive coatings optimized for friction and corrosion, while bearing surfaces receive coatings optimized for their mechanical contact requirements, achieving superior overall performance.

Inventive Principle:
Principle #3Local quality

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 solution effectively prevents unintended loosening, reduces reverse torque, and enhances abrasion and corrosion resistance, ensuring a reliable and secure pipe connection while allowing easy assembly and maintaining mechanical integrity.

Implementation Method 1

the first coating has a first friction coefficient μ1 and the second coating has a second friction coefficient μ2, and the first friction coefficient μ1 is larger than the second friction coefficient μ2

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

They can nevertheless be improved further with regard to optimization of their coatings. This is also true of their abrasion properties and corrosion properties in particular

Methodology Applied
Scientific EffectCorrosion resistance:

Implementation Method 3

They can nevertheless be improved further with regard to optimization of their coatings. This is also true of their abrasion properties and corrosion properties in particular

Methodology Applied
Scientific EffectAbrasion resistance: Abrasion

Data Source

PatentEP3652475B1A pipe connecting device with screw element for connecting pipes
Publication Date: 2022.06.29 TI AUTOMOTIVE HEIDELBERG
  • EP3652475B1 patent drawingFigure 1
  • EP3652475B1 patent drawingFigure 2~3

AI summary

A screw element for connecting pipes (2), preferably automotive pipes, wherein the screw element has at least one thread (3) and at least one thread-free contact surface (4), wherein the thread (3) is provided with a first coating (7) in at least one area, wherein at least one thread-free contact surface (4) is provided with a second coating (8) in at least one area, characterized in thatthe first coating (7) comprises at least 40 wt%, preferably at least 50 wt% of at least one epoxy compound, in particular at least one phenol-based epoxy compound and at least one lubricant.