Orbital Welding Head Oxygen Sensing via Optical Coupling

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Solution Overview

Problem

Existing orbital welding devices face issues with oxygen sensor damage from heat when inside the housing and measurement delays when outside, due to the need for cumbersome suction devices.

Innovation Solution

An orbital welding device with an optical oxygen sensor positioned outside the protective gas chamber, optically coupled via light guides, such as glass fibers, allowing for instantaneous measurements without a suction device and protecting the sensor from heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the oxygen sensor is arranged inside the housing forming a chamber for protective gas, then the measurement of oxygen concentration is direct and instantaneous, but the oxygen sensor is damaged due to the heat of the welding process

Engineering Contradiction:
Improvemeasurement delayVSAvoidsensor damage
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent uses optical coupling elements (light guides, optical fibers, or lenses) as intermediaries to transmit light from the measuring area inside the chamber to the oxygen sensor located outside the chamber. This intermediary system enables the sensor to measure oxygen concentration in the hot environment without being physically exposed to the heat, thus resolving the contradiction between instantaneous measurement and sensor protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the oxygen sensor is arranged outside the housing, then the sensor is protected from heat, but a suction device is required which is cumbersome and leads to measurement delay

Engineering Contradiction:
Improvesensor protectionVSAvoidsuction device
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the oxygen sensor from the protective gas chamber environment and places it outside the chamber where it is protected from heat. Instead of using a suction device to bring samples to the sensor, the patent uses optical coupling to enable direct measurement, thereby eliminating the cumbersome suction device and its associated measurement delays while maintaining sensor protection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical suction device system with an optical coupling system. Instead of using mechanical means (suction pumps, tubes, and flow systems) to transport gas samples to the sensor, the patent uses optical fields to transmit measurement information from the chamber to the sensor, eliminating mechanical complexity and measurement delays.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a suction device is used to bring gas samples to the sensor, then the sensor can be protected from heat, but the measurement is delayed and the device becomes cumbersome

Engineering Contradiction:
Improvesensor protectionVSAvoidmeasurement delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical suction device system with an optical coupling system. Instead of using mechanical means (suction pumps, tubes, and flow systems) to transport gas samples to the sensor, the patent uses optical fields to transmit measurement information from the chamber to the sensor, eliminating mechanical complexity and measurement delays.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables reliable and instantaneous oxygen concentration measurement during welding, preventing sensor damage and eliminating measurement delays, while maintaining a protective gas atmosphere with minimal residual oxygen.

Implementation Method 1

The measurement of the combustion parameters can be carried out by absorption spectroscopy

Methodology Applied
Scientific EffectAbsorption spectroscopy: Absorption Spectroscopy

Implementation Method 2

the optical coupling preferably takes place via one or more light guides routed along the cable or the gas line and at least partially connected, preferably inserted in the outermost or an inner cable sheath, preferably glass fibers

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Data Source

PatentEP3650155B1Orbital welding device with improved residual oxygen measuring
Publication Date: 2022.08.17 ILLINOIS TOOL WORKS INC
  • EP3650155B1 patent drawingFigure 1
  • EP3650155B1 patent drawingFigure 2
  • EP3650155B1 patent drawingFigure 3

AI summary

Orbital welding device (1), wherein the orbital welding device (1) comprises a welding power source (10) in a welding power source housing (11) and an orbital welding head (20) separate from the welding power source housing (11) and connected to the welding power source (10) by means of a cable (2), wherein the orbital welding head (20) comprises a pipe support (21) and a welding electrode holder (22) rotatably mounted relative to the pipe support (21) for holding the welding electrode (23), wherein the orbital welding device (1) comprises an electric motor (31) which is configured to drive the welding electrode holder (22) and thus rotate it relative to the pipe support (21),wherein the orbital welding head (20) or the cable (2) or a gas line to the orbital welding head (20) or the orbital welding device (1) has an optical oxygen sensor (40) in or on the welding power source housing (11) and the orbital welding head (20) has a chamber (50) for shielding gas which is configured to surround a welding electrode (23) of the orbital welding head (20) during a welding process and to substantially seal it off to the outside, wherein the optical oxygen sensor (40) is configured to measure an oxygen concentration in a measuring area (51) in the chamber (50), wherein the oxygen sensor (40) is arranged outside the chamber (50) and the oxygen sensor (40) is optically coupled to the measuring area (51) via an optical coupling.