Pulsed LED Lighting Unit with Liquid Cooling for Engine Interiors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing lighting units for internal combustion engines require large installation spaces and suffer from high light intensity losses due to inefficient light coupling, making them bulky and prone to errors, especially at high ambient temperatures.

Innovation Solution

A compact lighting unit with a pulsed LED lamp and a cooling channel arrangement that allows for effective heat dissipation, where the LED lamp is operated in a pulsed manner and cooled using a coolant supplied through a separate channel, enabling high light intensity and efficient heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a flash lamp or conventional lighting unit is used for illuminating the combustion chamber, then sufficient light intensity can be achieved, but the installation space requirement increases and the system becomes more complex

Engineering Contradiction:
Improvelight intensityVSAvoidinstallation space
Core Design Contradiction:
Illumination intensityVSVolume of stationary object

Solution Approach 1:

The LED lamp is operated in a pulsed manner with high current pulses during the combustion stroke, enabling high light intensity output only when needed. This periodic operation allows the use of a compact LED structure instead of a bulky continuous lighting system, resolving the contradiction between light intensity and installation space.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The operating parameters of the LED are dynamically changed by applying high current pulses during specific engine strokes. This parameter change enables the compact LED to generate sufficient light intensity on-demand, eliminating the need for large installation spaces required by conventional continuous lighting systems.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If the LED lamp is operated continuously at high intensity, then sufficient illumination is provided, but heat dissipation becomes problematic and service life decreases

Engineering Contradiction:
Improvelight intensityVSAvoidservice life
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The LED operates in periodic pulses with high intensity during combustion strokes followed by cooling periods during other strokes. This periodic operation pattern allows heat dissipation during off-periods, preventing thermal accumulation that would reduce reliability and service life, while still providing sufficient illumination intensity when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cooling channels continuously circulate coolant through the LED housing during all engine strokes, ensuring continuous heat removal. This continuous cooling action maintains the LED within safe operating temperature ranges even during high-intensity pulsed operation, preserving service life and reliability.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of operation

If coupling optics and light guides are used to feed light to the observation cavity, then the light source can be positioned outside the cavity, but light intensity losses increase significantly

Engineering Contradiction:
Improvelight source positioningVSAvoidlight intensity loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The LED lamp is extracted from the observation cavity and positioned in the housing outside the combustion chamber. The cooling channel arrangement is also extracted from the cavity space. This extraction eliminates the need for coupling optics and light guides, preventing light intensity losses while maintaining ease of operation through the rod-shaped housing design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The lighting function and cooling function are merged into a single integrated housing structure. The LED lamp and cooling channels are combined in one unit that can be positioned outside the observation cavity, eliminating the need for separate coupling optics and light guides, thus preventing light intensity losses.

Inventive Principle:
Principle #5Merging (Combining)

4Power

If the LED lamp is operated at high current pulses, then high light output is achieved, but heat release increases requiring effective cooling

Engineering Contradiction:
Improvelight outputVSAvoidheat release
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

A liquid cooling system using coolant circulation through channels in the LED housing is implemented. The coolant absorbs heat from the LED during high-current pulsed operation, effectively managing the increased heat release while maintaining high light output. The coolant flow rate and thermal properties are optimized to handle the thermal load from high-power LED operation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The cooling channels act as an intermediary thermal management system between the high-power LED and the external environment. The coolant serves as a thermal mediator, transferring heat away from the LED during high-current pulses, enabling sustained high light output without excessive temperature rise that would damage the LED.

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 solution provides a compact, high-intensity lighting system capable of operating effectively at high temperatures with reduced light losses and improved heat dissipation, allowing for precise illumination and extended service life.

Implementation Method 1

a cooling channel arrangement, in particular for a cooling liquid, for cooling the light source

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

The lighting unit is supplied with coolant, for example coolant, in the area of the second end of the housing

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3769140B1Lighting unit for interiors of machines
Publication Date: 2021.09.15 AVL LIST GMBH
  • EP3769140B1 patent drawingFigure 1~3
  • EP3769140B1 patent drawingFigure 4~5
  • EP3769140B1 patent drawingFigure 6~10

AI summary

The invention relates to a lighting unit (1) for interiors of machines, in particular internal combustion engines, wherein the lighting unit (1) has a housing (2) in which at least one light source (6) which is formed by an LED lamp (5) is arranged, wherein the housing (2) has, for cooling the light source (6), a cooling duct arrangement (7), in particular for a cooling liquid, wherein a cooling section (8) of the cooling duct arrangement (7) is arranged in the region of the light source (6). In order to render possible a compact lighting unit (1) with high light intensities, provision is made for the LED lamp (5) to be able to be operated in a pulsed manner. The invention further relates to a method for illuminating interiors of machines using a lighting unit (1) of this kind.