In-line Laser Hardening with Distortion Compensation

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Solution Overview

Problem

State-of-the-art in-line manufacturing methods are limited in processing capabilities and result in long processing times and high space requirements, as they require pre-completion of important steps before the workpiece can be processed, leading to inefficiencies and increased costs.

Innovation Solution

An in-line method that integrates a compensation step for laser hardening distortion within the same work station, using additional laser hardening tracks to counteract distortion, eliminating the need for separate hardening and mechanical post-processing, and allowing for real-time control of laser parameters to achieve targeted hardness profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If separate laser hardening process is used before in-line manufacturing, then the workpiece can be hardened, but the overall machining time increases and space requirements increase

Engineering Contradiction:
Improvehardening qualityVSAvoidoverall machining time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The patent combines the laser hardening process with the in-line manufacturing process by integrating a laser device into one of the workstations. This allows the hardening step to be performed simultaneously with other manufacturing operations, eliminating the need for separate pre-hardening steps and reducing overall machining time while maintaining hardening quality.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If separate laser hardening process is used before in-line manufacturing, then the workpiece can be hardened, but the space requirements increase

Engineering Contradiction:
Improvehardening qualityVSAvoidspace requirement
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The patent merges the laser hardening station with existing in-line manufacturing workstations, utilizing the same physical space and infrastructure. This integration eliminates the need for separate dedicated hardening areas, thereby reducing overall space requirements while maintaining the ability to perform quality hardening.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If laser hardening is performed, then the workpiece areas are hardened, but distortion occurs requiring additional post-processing

Engineering Contradiction:
Improvehardening qualityVSAvoidworkpiece geometry
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies preliminary anti-action by performing a compensation step where additional laser tracks are applied to counteract the distortion caused by the initial hardening process. This compensatory hardening is planned and executed within the same in-line process, preventing the need for subsequent mechanical post-processing and maintaining workpiece geometry precision.

Inventive Principle:
Principle #9Preliminary anti-action

4Strength

If multiple separate processes are used for hardening and post-processing, then the workpiece can be hardened and corrected, but energy consumption increases

Engineering Contradiction:
Improvehardening qualityVSAvoidenergy consumption
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple processing steps (hardening and compensation) into a single integrated laser processing sequence within the in-line manufacturing system. This eliminates the need for separate hardening and post-processing operations, thereby reducing energy consumption while maintaining the ability to achieve both hardening quality and geometric precision.

Inventive Principle:
Principle #5Merging (Combining)

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 integration significantly reduces cycle times, eliminates the need for separate hardening processes, saves space, and reduces energy consumption, while ensuring high-quality and cost-effective production by maintaining the target geometry and adjusting hardness through controlled laser application.

Implementation Method 1

at least one area of the workpiece or assembly is hardened by applying at least one laser hardening track using a laser device

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

The compensatory hardening track(s) stretches the workpiece in the opposite direction, thereby compensating for the distortion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3068911B1In-line method and in-line production plant
Publication Date: 2019.10.30 STIWA HLDG
  • EP3068911B1 patent drawingFigure 1
  • EP3068911B1 patent drawingFigure 2~4
  • EP3068911B1 patent drawingFigure 5~6

AI summary

The invention relates to an in-line method for producing workpieces or assemblies (2), in which method workpieces or assemblies (2) pass through a number of successive work stations (4) by means of a conveyor device (3). Said method is characterised by a hardening step that is carried out in one of the work stations (4), during which step at least one region of the workpiece or assembly (2) is hardened by the application of at least one laser hardening trace (6) by means of a laser device (5), in particular a laser with programmable focussing optics (PFO), or a linear laser. The invention also relates to a corresponding in-line production plant.