Protective Gas Mouthpiece Geometry for Uniform Welding Flow

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Solution Overview

Problem

Existing protective gas mouthpieces for joining processes, such as arc stud welding, have interfering contours that hinder gas flow control, leading to suboptimal joint quality and inefficiencies in gas distribution.

Innovation Solution

A protective gas mouthpiece with a compact design featuring a base member with a flattened portion and four protective gas supply channels, arranged in mirror symmetry, along with a resistance element in the distribution chamber to ensure even gas flow, and manufactured using 3D printing for complex geometries, reducing interference and enhancing gas flow orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional protective gas mouthpiece with cylindrical base member is used, then the gas flow control is hindered by interfering contours, but the manufacturing process is simpler

Engineering Contradiction:
Improvegas flow controlVSAvoidmouthpiece geometry
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The base member is segmented into a cylindrical portion and a flattened portion, allowing the gas supply channels to be arranged in specific orientations. This segmentation enables better gas flow control by directing protective gas radially inward toward the cleaning space without interference from the workpiece, while maintaining manufacturing feasibility through defined geometric zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mouthpiece geometry transitions from a purely cylindrical form to a flattened configuration in the radial direction. This dimensional change allows the gas supply channels to be positioned and oriented more effectively, creating unobstructed radial gas flow paths that improve protective gas distribution in the cleaning space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the base member has a flattened portion with specific channel geometry, then unwanted gas streams are avoided and joint quality improves, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvejoint qualityVSAvoidmouthpiece fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The gas supply channels are given specific local geometries including bent portions with defined curvature radii. These localized geometric features direct the protective gas flow in controlled paths that avoid creating unwanted streams, ensuring reliable joint quality in critical areas while maintaining overall manufacturability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The channel geometry parameters are optimized with specific curvature radii and bend angles. By carefully selecting these geometric parameters, the gas flow is directed to achieve uniform distribution in the cleaning space without creating turbulent or unwanted streams, thereby improving joint reliability.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If four protective gas supply channels are used with mirror symmetry, then gas distribution uniformity is improved, but the device complexity increases

Engineering Contradiction:
Improvegas distribution uniformityVSAvoidchannel arrangement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

While the overall arrangement exhibits mirror symmetry for balance, the individual channels are asymmetrically oriented relative to the flattened portion. This controlled asymmetry in channel positioning and angulation allows each channel to direct gas flow optimally into the cleaning space, achieving uniform distribution across the workpiece surface.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The mirror-symmetric arrangement of the four channels creates a balanced gas distribution system where opposing channels provide equivalent flow paths. This equipotential-like symmetry ensures that protective gas is distributed uniformly across the cleaning space, improving joint quality through consistent gas coverage.

Inventive Principle:
Principle #12Equipotentiality

4Adaptability or versatility

If the mouthpiece is designed for compact installation in narrow spaces, then installation flexibility is improved, but the gas flow control becomes more challenging

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidgas flow control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The flattened portion extends the mouthpiece geometry in the radial direction rather than increasing axial length. This dimensional approach allows the gas supply channels to be positioned and oriented for optimal flow control while keeping the overall axial footprint compact, enabling installation in narrow spaces without sacrificing gas flow precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 improves gas flow control and joint quality by minimizing unwanted gas streams and ensuring uniform gas distribution, allowing for better control over the joining process and reduced maintenance needs.

Implementation Method 1

Three protective gas supply channels (38a, 38b, 38c) are directed into the cleaning space (26) such that a main flow direction of the protective gas in a radial centre (27) of the cleaning space is orientated in a substantially radial and unidirectional manner

Methodology Applied
Scientific EffectPressure-driven gas flow: Pressure Gradient

Data Source

PatentEP4147815B1Protective gas mouthpiece, joining device and joining method
Publication Date: 2024.06.19 NEWFREY LLC
  • EP4147815B1 patent drawingFigure 1~2
  • EP4147815B1 patent drawingFigure 3~4
  • EP4147815B1 patent drawingFigure 5A~5B

AI summary

The present application relates to a method of carrying out a welding process using protective gas by means of a protective gas mouthpiece (18), a joining device and to a protective gas mouthpiece (18). the protective gas mouthpiece (18) comprises a base member (20), at least two protective gas supply channels (38a, 38b, 38c, 38d), and a gas distributor member (44). The gas distributor member (44) comprises a distribution chamber (46) and the inlets of all the protective gas supply channels open into the distribution chamber (46). The base member (20) comprises a flattened portion, and the inlets are arranged on the flattened portion and the gas distributor member (44) is fixed to the flattened portion, and wherein each protective gas supply channel (38a, 38b, 38c, 38d) comprises at least one straight portion and one bent portion such that an interfering contour for the gas flow is significantly reduced.