Laser Head Nozzle Sealing for Clean Optical Paths

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Solution Overview

Problem

Existing laser processing apparatuses face challenges in maintaining airtightness within the processing head due to loose thread fastening and lack of sealing between the protection glass and lens holder, allowing spatters and fumes to enter and compromising the cleanliness of the optical system.

Innovation Solution

A laser processing apparatus design that includes a pressure chamber between the head main body and nozzle, supplied with air or assist gas, and featuring communication holes and a supply passage to maintain airtightness and keep the optical system clean, with a seal member pressing against the protection glass to prevent contamination and secure fastening despite vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If thread fastening is used to couple the nozzle and lens holder, then assembly is simple and disassembly is easy, but the fastening may come loose due to vibrations and airtightness cannot be maintained

Engineering Contradiction:
Improveease of assembly and disassemblyVSAvoidairtightness maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The sealing function is segmented from the fastening function. The O-ring seal member provides sealing between the nozzle and lens holder independently of the thread fastening connection, allowing the fastening mechanism to remain simple while the sealing mechanism ensures reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An O-ring seal member is introduced as an intermediary element between the nozzle and lens holder to provide the sealing function that thread fastening alone cannot ensure, while maintaining the simplicity of thread-based assembly and disassembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If no sealing is provided between protection glass and lens holder, then assembly is simple, but spatters and fumes can enter the lens holder and contaminate the optical system

Engineering Contradiction:
Improvesealing structure complexityVSAvoidoptical system contamination
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The O-ring seal member acts as an intermediary barrier between the external environment (where spatters and fumes exist) and the lens holder (containing the optical system), preventing contamination while adding minimal structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The O-ring seal member is a flexible elastic body that conforms to the mating surfaces between the nozzle and lens holder, creating an effective seal against spatters and fumes without requiring complex rigid sealing structures.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If excessive tightening force is applied during thread fastening, then airtightness is improved, but the threads may be damaged

Engineering Contradiction:
ImproveairtightnessVSAvoidthread integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sealing function is separated from the fastening function. The O-ring seal member provides the sealing effect without requiring excessive tightening force, thus protecting the threads from damage while maintaining airtightness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elastic O-ring seal member acts as a cushioning element that compensates for minor misalignments and surface irregularities, allowing adequate sealing without requiring excessive fastening force that could damage the threads.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 effectively maintains airtightness within the processing head, preventing spatters and fumes from entering and ensuring the optical system remains clean, while allowing for easy replacement of the protection glass and reducing the risk of thread damage from excessive tightening.

Implementation Method 1

a pressure chamber which is supplied with air or assist gas

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Implementation Method 2

an optical system which a laser beam enters and which condenses the laser beam

Methodology Applied
Scientific EffectLaser beam condensation: Focusing

Data Source

PatentEP3096918B1Laser processing apparatus
Publication Date: 2021.03.31 TOYOTA JIDOSHA KK
  • EP3096918B1 patent drawingFigure 1
  • EP3096918B1 patent drawingFigure 2~3
  • EP3096918B1 patent drawingFigure 4~5

AI summary

A laser processing apparatus includes: a head main body (20) housing an optical system; and a nozzle (30) that is fastened to the head main body (20) by thread fastening and that applies the laser beam to a workpiece (W). The nozzle (30) has a nozzle hole (31) through which the laser beam passes. A pressure chamber (36) is formed between the head main body (20) and the nozzle (30). The pressure chamber (36) is a space surrounded by a bottom surface (23b) of the head main body (20), the bottom surface (23b) intersecting with a fastening direction in which the head main body (20) and the nozzle (30) are fastened together by thread fastening, and a bottom surface (34a) of the nozzle (30), the bottom surface (34a) intersecting with the fastening direction. The pressure chamber (36) is supplied with air or assist gas. The nozzle (30) has a communication hole (35) that provides communication between the pressure chamber (36) and the nozzle hole (31).