Laser Beam Angle And Focus Control for Uniform 3D Machining

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Solution Overview

Problem

Machining difficult-to-machine materials with curvature using laser beams is challenging due to variations in irradiation diameter and incidence angle, leading to reduced productivity compared to flat surfaces.

Innovation Solution

A laser machining apparatus with a focus position control mechanism to adjust the divergence angle and incident diameter of the laser beam, and an emitting angle control mechanism to maintain uniform machining conditions over curved surfaces, using a galvano scanner and incident position control mechanism to ensure consistent laser beam incidence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the workpiece or optical system is rotated to uniformize irradiation diameter and incidence angle on curved surfaces, then machining condition uniformity is improved, but device complexity and operational difficulty increase

Engineering Contradiction:

Improvemachining condition uniformityVSAvoidworkpiece or optical system rotation

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of rotating the workpiece or optical system to achieve uniform machining conditions, the patent inverts the approach by making the laser beam itself adaptable through optical elements. The variable focal length lens and beam expanding/expanding elements modify the laser beam parameters dynamically, eliminating the need for mechanical rotation while maintaining uniform irradiation conditions on curved surfaces.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs dynamic optical elements including a variable focal length lens whose focal length can be changed, and beam expanding/expanding elements that can adjust beam diameter. These dynamic optical components allow the system to adapt to different positions on curved surfaces without mechanical rotation, maintaining uniform machining conditions through real-time optical parameter adjustment.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If the laser beam is swept multiple times over difficult-to-machine materials, then thermal effects are reduced, but productivity decreases due to inability to maintain uniform conditions on curved surfaces

Engineering Contradiction:

Improvethermal effectsVSAvoidmachining speed

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes optical parameters dynamically during the sweeping process. By adjusting the focal length of the lens and the beam diameter through expanding/expanding elements, the system maintains optimal irradiation conditions at different positions on curved surfaces. This allows multiple sweeps to be performed with consistent parameters, reducing thermal effects while maintaining higher productivity through uniform machining conditions throughout the process.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the irradiation diameter and incidence angle are allowed to change on curved surfaces, then device complexity is reduced, but machining precision and quality deteriorate

Engineering Contradiction:

Improveoptical system configurationVSAvoidmachining quality

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent introduces intermediary optical elements between the laser source and the workpiece. The variable focal length lens and beam expanding/expanding elements act as mediators that transform the laser beam parameters to compensate for surface curvature effects. These intermediaries enable uniform machining conditions without requiring complex mechanical systems, maintaining machining quality while avoiding excessive device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 apparatus achieves uniform machining conditions and increased productivity for three-dimensional machining by maintaining consistent irradiation diameter and incidence angle over curved surfaces, reducing the need for workpiece or optical system rotation.

Implementation Method 1

a focusing lens to irradiate a workpiece with the laser beam

Methodology Applied

Scientific EffectFocusing: Focusing

Implementation Method 2

a laser beam deflector to deflect the laser beam before the laser beam is incident on the focusing lens

Methodology Applied

Scientific EffectLight reflection/deflection: Reflection

Data Source

PatentUS11446760B2Laser machining apparatus and laser machining method

Publication Date: 2022.09.20 MITSUBISHI ELECTRIC CORP

AI summary

A laser machining apparatus includes: a laser oscillator to emit a laser beam; a focusing lens to irradiate a workpiece with the laser beam; a focus position control mechanism disposed between the laser oscillator and the focusing lens and disposed on the optical path of the laser beam and that controls the divergence angle of the laser beam and the incident diameter of the laser beam incident on the focusing lens; a laser beam deflector to deflect the laser beam before the laser beam is incident on the focusing lens; and an emitting angle control mechanism to control the emitting angle of the laser beam that exits from the focusing lens after being deflected by the laser beam deflector.