Pulsating Punching for Coated Cut Surface Quality

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Solution Overview

Problem

Existing punching machines struggle to achieve improved surface quality of workpiece cut surfaces and efficiently transfer a metallic surface coating to the cut surface during the punching process, leading to suboptimal corrosion resistance and increased rework requirements.

Innovation Solution

A punching machine with a first punching element driven in a pulsating manner, featuring a cutting gap of 0.5% of the material thickness, and a control device that manages the pulsating drive to relax the material and improve deformation behavior, thereby enhancing surface quality and coating transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional shear cutting with a cutting gap of 4-5% of material thickness is used, then the punching machine can operate with standard setup, but the cut surface quality is poor with cracks, tears, and burrs

Engineering Contradiction:
Improvecut surface qualityVSAvoidpunching machine configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by reducing the cutting gap from the conventional 4-5% of material thickness to 0.5% of material thickness. This significant parameter change enables high-quality cut surfaces free of cracks and tears while maintaining standard punching machine operation without requiring complex additional equipment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements periodic action through the pulsating drive mechanism that alternates between feed movement (punching phase) and return movement (relaxation phase). This periodic cycling allows the material to relax between punching cycles, preventing work hardening and crack formation while achieving complete coating transfer to the cut surface

Inventive Principle:
Principle #19Periodic action

2Manufacturing precision

If fine blanking process with V-shaped ring is used, then cut surface quality is improved, but the process is limited to material thickness more than 1 mm and requires triple-action press

Engineering Contradiction:
Improvecut surface qualityVSAvoidmaterial thickness range and equipment requirement
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent extracts and eliminates the V-shaped ring from the punching process, achieving high-quality cut surfaces without this restrictive component. This allows the process to be applied to thin-walled workpieces (including foil and sheet metal) that cannot accommodate a V-shaped ring, while using standard punching press equipment rather than requiring a triple-action press

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the cutting gap parameter to 0.5% of material thickness, which enables high-quality cutting across a wide range of material thicknesses including thin-walled structures. This parameter change eliminates the need for the V-shaped ring and triple-action press, providing versatility for both thin and thick materials

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If counter cutting with two or three stages is used, then burrs are eliminated, but only 50% smooth cutting rate is achieved with fracture zone remaining

Engineering Contradiction:
Improvesmooth cut surface proportionVSAvoidcutting efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent achieves 100% smooth cut surface proportion by implementing a cutting gap of 0.5% of material thickness with pulsating drive. This single-stage process eliminates the fracture zone completely while maintaining high productivity, avoiding the need for multiple counter cutting stages

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If cutting punches are driven with time delay during punching, then punching action is achieved, but workpiece section is deformed or broken leading to work hardening and cracks

Engineering Contradiction:
Improvepunching actionVSAvoidworkpiece integrity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses synchronous pulsating drive where both cutting punches move in sync during the feed movement phase and return simultaneously during the return movement phase. This synchronized periodic action prevents workpiece deformation and cracking while achieving effective punching, eliminating the need for time-delayed operation

Inventive Principle:
Principle #19Periodic action

5Quantity of substance

If standard cutting gap of 4-5% of material thickness is used, then punching machine operates conventionally, but metallic surface coating transfer to cut surface is insufficient

Engineering Contradiction:
Improvemetallic surface coating transferVSAvoidcutting gap specification
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent changes the cutting gap parameter to 0.5% of material thickness, which enables complete transfer of the metallic surface coating to the cut surface. This parameter change achieves up to 95% coating coverage on the cut surface, significantly improving corrosion resistance without requiring additional coating application equipment

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 solution achieves improved surface quality with reduced cold strength and increased deformation behavior, allowing for up to 95% of the cut surface to be coated with metallic surface coating particles, thereby enhancing corrosion resistance and reducing rework.

Implementation Method 1

the first punching element is driven during the punching process in a pulsating manner, with a feed movement of the first punching element toward the workpiece and a return movement of the first punching element away from the workpiece

Methodology Applied
Scientific EffectStress Relaxation: Stress Relaxation

Implementation Method 2

allowing for up to 95% of the cut surface to be coated with metallic surface coating particles

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4541479A1Punching machine
Publication Date: 2025.04.23 CREATIVE AUTOMATION GMBH & CO KG
  • EP4541479A1 patent drawingFigure 1
  • EP4541479A1 patent drawingFigure 2
  • EP4541479A1 patent drawingFigure 3

AI summary

A punching machine is provided for punching a workpiece with a metallic surface coating, wherein the punching machine comprises a first punching element for punching the workpiece, a first drive element associated with the first punching element which drives the first punching element for punching the workpiece along at least one punching axis which is oriented perpendicular to a longitudinal axis of the workpiece to be punched, at least one hold-down device for fixing the workpiece during the punching process and at least one die.The punching machine further comprises a control device configured to control the first drive element such that, during the punching process, the first punching element is driven in a pulsating manner with a feed movement towards the workpiece and a return movement away from the workpiece in the opposite direction to the feed movement. A cutting gap provided between the first punching element and the die along the longitudinal axis of the workpiece to be punched is 0.5% of the workpiece material thickness along the punching axis.