Stranded Cable Welding with Sheared End Face

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Solution Overview

Problem

Existing methods for connecting electrical cables to contact pieces, such as crimping and welding, are complex and prone to errors like oxidation and weld spatter, especially when using aluminum conductors, which can impair conductivity and tensile strength.

Innovation Solution

The axial ends of stranded electrical wires are fixed with a clamping tool, sheared to form a closed end face, and then inserted into a recess on a contact piece, where they are welded using radiant energy, with the end face angled to improve insertion and welding quality, and a coating like nickel may be removed to enhance conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aluminum conductors are used to reduce weight and improve conductivity, then electrical conductivity is improved, but an electrically insulating oxide layer quickly forms on the surface which impairs conductivity and welding

Engineering Contradiction:
Improveelectrical conductivityVSAvoidoxide layer formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by performing laser welding immediately after cable stripping and before the aluminum oxide layer can form. The entire process is completed within a time window of less than one second, preventing oxidation from occurring. This is achieved through a automated stripping-welding system where the cable is stripped and welded in continuous sequence without exposure to air.

Inventive Principle:
Principle #10Preliminary action

2Strength

If laser welding is used to produce a durable electrical connection, then connection strength is improved, but weld spatter, oxidation or traces of smoke can affect the cable and surrounding areas

Engineering Contradiction:
Improveconnection strengthVSAvoidweld spatter and smoke
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful laser welding spatter and smoke into a beneficial process by containing them within a closed welding chamber. The harmful byproducts are directed toward a water-cooled shield that captures and neutralizes them, while the laser energy successfully creates a strong weld connection between the cable and contact piece.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If the radiation source is positioned to weld through the contact piece, then welding can be performed, but radiation may escape through the welding chamber lock posing safety risks

Engineering Contradiction:
Improvewelding feasibilityVSAvoidradiation escape
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by positioning the laser radiation source and welding chamber at an angled orientation rather than in a straight line. The laser enters the welding chamber through a window at an angle, and the welded cable is removed through a different angled path. This asymmetric arrangement ensures that radiation cannot escape directly through the lock or opening, eliminating the safety hazard while maintaining welding effectiveness.

Inventive Principle:
Principle #4Asymmetry

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

This method enhances process stability and connection quality by creating a clean, oxide-free surface for welding, improving tensile strength and electrical conductivity while preventing radiation escape and reducing shadowing during the welding process.

Implementation Method 1

the axial ends of the plurality of stranded electrical wires protruding axially from the clamping tool are sheared off in the transverse direction with a cutting tool

Methodology Applied
Scientific EffectShear stress: Shear Stress

Implementation Method 2

the closed end face arranged in the recess is melted by means of radiant energy from radiation directed onto the end face

Methodology Applied
Scientific EffectRadiation: Radiation

Implementation Method 3

the axial end of the plurality of electrical stranded wires is inserted into the recess, and that the plurality of stranded wires are welded to the contact piece, in that the closed end face arranged in the recess is melted by means of radiant energy from radiation directed onto the end face

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 4

the axial ends of the plurality of electrical strands are inserted into the recess and are pressed to produce an electrical connection with the crimp tab

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP4216371A1Method for connecting an electrical cable with a contact piece
Publication Date: 2023.07.26 KOMAX HOLDING
  • EP4216371A1 patent drawingFigure 1a~1b
  • EP4216371A1 patent drawingFigure 2a~2f
  • EP4216371A1 patent drawingFigure 3a~4b

AI summary

To improve the process stability during the production of a connection between a contact piece (5) and a cable (1), as well as the quality of such a connection, it is provided that the axial ends of the majority of the electrical strands (3) of the cable (1) are fixed with a clamping tool (33) before being inserted into the recess (8) of a crimping area (6), so that the axial ends of the majority of the electrical strands (3) protrude axially from the clamping tool (33) by a length (L) and the axially protruding ends of the majority of the strands (3) are sheared off transversely with a cutting tool (32), so that a closed end face (9) is formed at the axial end of the strands (3) that the axial end of the majority of the electrical strands (3) is inserted into the recess (8) and the majority of the strands (3) are welded to the contact piece (5) by the closed,The end face (9) arranged in the recess (8) is melted by the radiation energy of a radiation directed at the end face (9).