Rotating Prism Laser Machining for Precision With Lower Heat Impact

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Solution Overview

Problem

Existing machining devices require complex configurations to achieve high-precision machining with laser beams, which complicates the device setup and operation.

Innovation Solution

A machining device with a modular design that includes a collimating optical system, a laser beam rotating unit with adjustable prisms, and a converging optical system, allowing for precise control of the laser beam's path and power to optimize machining conditions based on the workpiece's material and thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a laser beam rotating unit with multiple prisms and rotation mechanisms is used, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvemachining precisionVSAvoiddevice configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The optical system is divided into separate functional modules: a collimating optical system, a laser beam rotating unit with prisms, and a converging optical system. This segmentation allows each component to be optimized independently while maintaining overall system precision, resolving the contradiction between machining precision and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a laser beam rotating unit with prisms that can be rotated to dynamically adjust the laser beam's path and focal point position. This dynamic adjustment capability enables precise machining without requiring complex fixed mechanical positioning systems, thereby improving machining precision while managing device complexity.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the laser beam is focused to a small spot diameter for precise machining, then manufacturing precision is improved, but the heat-affected zone increases

Engineering Contradiction:
Improvespot diameter controlVSAvoidheat-affected layer thickness
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic rotation of the laser beam across the workpiece surface rather than continuous stationary focusing. This periodic scanning motion allows heat to dissipate between irradiation cycles, reducing the cumulative heat-affected zone while maintaining precise spot diameter control for high manufacturing precision.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The rotating laser beam provides continuous coverage of the machining area, ensuring uniform energy distribution and preventing localized overheating. This continuous motion maintains precise spot control while minimizing the heat-affected layer thickness through constant movement and heat dissipation.

Inventive Principle:
Principle #20Continuity of useful action

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 simplifies the device configuration, enhances precision, and enables high-speed machining with reduced heat-affected zones, improving overall machining quality and efficiency.

Implementation Method 1

a collimating optical system that is arranged to collimate the laser beam

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 2

The laser beam rotating unit has a first prism that is arranged to refract the laser beam

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

a second prism that is disposed to face the first prism and is arranged to refract the laser beam output from the first prism

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

a converging optical system that is arranged to converge the laser beam rotated by the laser beam rotating unit to a focal point

Methodology Applied
Scientific EffectFocusing: Focusing

Implementation Method 5

cuts or pierces a hole in a workpiece by irradiating the workpiece with a laser beam

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 6

a machining method that machine a workpiece by irradiating the workpiece with a laser beam

Methodology Applied
Scientific EffectAblation: Laser Ablation

Data Source

PatentEP2923791B1Laser machining method
Publication Date: 2023.10.25 MITSUBISHI HEAVY IND LTD
  • EP2923791B1 patent drawingFigure 1
  • EP2923791B1 patent drawingFigure 2
  • EP2923791B1 patent drawingFigure 3

AI summary

Provided are a machining device and a machining method in which machining of higher precision can be performed with a simple configuration. The machining device has an irradiation head (16) and a controller; and the irradiation head (16) can be divided into a collimate optical system, a laser revolving unit (35), and a light collection optical system (37). The laser revolving unit (35) has a first prism (51), a second prism (52), a first rotation mechanism (53), and a second rotation mechanism (54). The controller controls the rotational speeds and the difference in phase angles of the first prism (51) and the second prism (52), on the basis of at least the relationship between a heat affected layer of a member to be machined and the revolving speed of the laser.