Laser Beam Optical Unit With Non-Uniform Spot Energy Distribution
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Solution Overview
Problem
Conventional laser machining using annular laser beams struggles to prevent molten workpieces from remaining on cut surfaces or hole portions when the movement speed of the laser beam is fast, leading to decreased throughput and compromised machining quality.
Innovation Solution
A laser beam irradiation optical unit with an energy intensity distribution adjustment mechanism that adjusts the energy intensity distribution of the laser beam to be non-uniform, allowing for effective melting and blowing off of molten workpieces in the rear region of the spot, even at high movement speeds, using mechanisms such as laser beam direction adjustment, collimating lenses, and condensing lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the movement speed of the laser beam is increased to improve throughput, then productivity increases, but molten workpiece remains on the cut surface or hole portion deteriorating machining quality
Solution Approach 1:
The patent applies local quality by creating a non-uniform energy intensity distribution within the laser beam spot, specifically forming a ring-shaped high energy intensity region and a central low energy intensity region. This local differentiation allows the rear portion of the spot to effectively blow off molten workpiece while the front portion maintains controlled melting, enabling high-speed machining without sacrificing quality.
Solution Approach 2:
The patent changes the energy intensity distribution parameter from uniform to non-uniform by introducing optical elements (such as phase modulation plates or diffractive optical elements) that reshape the beam profile. This parameter change creates distinct high and low energy regions within the spot, allowing the system to maintain effective molten material removal even at increased movement speeds.
2Manufacturing precision
If an annular laser beam with uniform energy intensity distribution is used to blow off molten workpiece, then machining quality improves at low speed, but molten workpiece remains on the cut surface when movement speed increases
Solution Approach 1:
The patent modifies the uniform annular distribution by introducing a central low energy intensity region, creating a more sophisticated local quality pattern. This results in a ring-shaped high energy region that effectively removes molten material while the central region prevents excessive melting and spatter, enabling the system to maintain machining quality at higher movement speeds.
Solution Approach 2:
The patent segments the energy intensity distribution into distinct regions: a central low energy intensity region and a surrounding ring-shaped high energy intensity region. This segmentation allows different parts of the laser spot to perform different functions - the central region controls melting while the annular region performs material removal, enabling high-speed machining with maintained quality.
3Manufacturing precision
If a spot-shaped laser beam is used for precise machining, then manufacturing precision is achieved, but molten workpiece accumulates on the cut surface or hole portion
Solution Approach 1:
The patent transforms the uniform spot-shaped beam into a non-uniform distribution with a central low energy region and a ring-shaped high energy region. This local quality differentiation allows the central region to maintain precise machining capability while the surrounding annular region provides the necessary energy for blowing off molten workpiece, eliminating accumulation without sacrificing precision.
Solution Approach 2:
The patent segments the spot-shaped beam energy distribution into functional zones: a central region for controlled melting and precise machining, and an annular region for molten material removal. This segmentation resolves the contradiction by assigning different roles to different parts of the beam, enabling both precision and effective material ejection.
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 solution ensures that molten workpieces do not remain on cut surfaces or hole portions, maintaining high machining quality and increasing throughput during laser machining, even at increased laser beam movement speeds.
Implementation Method 1
The laser beam condenses at one point and a workpiece is irradiated with the laser beam, thereby rapidly increasing a surface temperature of the workpiece and melting or evaporating an irradiated surface of the workpiece
Implementation Method 2
The laser beam condenses at one point
Implementation Method 3
U.S. Pat. No. 9285593 discloses an optical system in which a function of shifting a phase of a laser beam is introduced into the optical system and a phase difference is provided in a part of a light flux of the laser beam
Implementation Method 4
the energy intensity distribution adjustment mechanism adjusts the energy intensity distribution of the laser beam at the spot so as to be non-uniform
Data Source
AI summary
Adopted is a laser beam irradiation optical unit for forming a spot on an object to be machined and irradiating the object to be machined with a laser beam emitted from a laser oscillator to perform laser machining including an energy intensity distribution adjustment mechanism that adjusts an energy intensity distribution of the laser beam at the spot in an irradiation trajectory of the laser beam from the laser oscillator to the object to be machined, in which the energy intensity distribution adjustment mechanism adjusts the energy intensity distribution of the laser beam at the spot so as to be non-uniform.