Dual-Spark Engine Combustion Layout for Lower Injector Heat

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Solution Overview

Problem

Existing internal combustion engines face challenges in achieving low thermal load on fuel injectors and spark plugs while ensuring excellent mixture formation in the combustion chamber.

Innovation Solution

The fuel injector is positioned on the side facing away from the exhaust port openings, and the spark plugs are arranged between intake and exhaust port openings, with one spark plug's ignition point located in a pre-chamber fluidically connected to the combustion chamber, reducing thermal stress and enhancing mixture formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the fuel injector is positioned near the exhaust port openings to achieve compact engine design, then the engine size is reduced, but the thermal load on the fuel injector increases

Engineering Contradiction:

Improveengine sizeVSAvoidthermal load on fuel injector

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The patent positions the fuel injector between two imaginary parallel planes that are spaced apart and parallel to the longitudinal center axis of the cylinder, running between the intake port openings and between the exhaust port openings. This spatial arrangement in a specific dimensional zone allows the injector to be compactly positioned while maintaining adequate distance from exhaust ports to reduce thermal load.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Power

If the spark plugs are positioned close to the combustion chamber to achieve high power density, then the power output is increased, but the thermal load on the spark plugs increases

Engineering Contradiction:

Improvepower densityVSAvoidthermal load on spark plugs

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The patent uses two separate spark plugs (first and second spark plugs) positioned at different locations between the imaginary parallel planes. This segmentation allows each spark plug to be optimally positioned for ignition while distributing the thermal load across multiple components rather than concentrating it on a single spark plug.

Inventive Principle:

Principle #1Segmentation

3Temperature

If the fuel injector is positioned on the side facing away from exhaust port openings to reduce thermal load, then the thermal stress on the injector is reduced, but the mixture formation in the combustion chamber may be affected

Engineering Contradiction:

Improvethermal stress on fuel injectorVSAvoidmixture formation quality

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The patent specifies that the fuel injector is positioned on the side facing away from the exhaust port openings of the imaginary transverse median plane. This localized positioning strategy ensures that the injector operates in a cooler thermal environment while still being able to effectively deliver fuel into the combustion chamber for proper mixture formation.

Inventive Principle:

Principle #3Local quality

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 configuration achieves high power density and efficient combustion with reduced thermal load on components, enabling efficient operation and compact engine design.

Implementation Method 1

a fuel injector for introducing fuel into the combustion chamber to produce a fuel-air mixture

Methodology Applied

Scientific EffectFuel injection: Injector

Implementation Method 2

a first spark plug and a second spark plug for igniting the fuel-air mixture

Methodology Applied

Scientific EffectIgnition: Electric Spark

Implementation Method 3

for igniting the fuel-air mixture

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 4

an ignition point of the first spark plug is arranged outside the combustion chamber in a pre-chamber fluidically connected to the combustion chamber

Methodology Applied

Scientific EffectFluid connection:

Data Source

PatentEP4419783B1Internal combustion engine and method for operating an internal combustion engine

Publication Date: 2026.01.21 AUDI AG

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AI summary

The invention relates to an internal combustion engine (1) comprising: at least one cylinder (3) having a combustion chamber (4), wherein a first inlet channel (10) having a first inlet valve (18) opens into the combustion chamber (4) via a first inlet channel mouth opening (14) and a second inlet channel (11) having a second inlet valve (19) opens into the combustion chamber via a second inlet channel mouth opening (15), and a first outlet channel (12) having an outlet valve (20) leads out of the combustion chamber (4) via a first outlet channel (16) and a second outlet channel (13) having a second outlet valve (21) leads out of the combustion chamber via a second outlet channel mouth opening (17); a fuel injector (22) for introducing fuel into the combustion chamber (4) in order to produce a fuel–fresh gas mixture; and a first spark plug (25) and a second spark plug (26) for igniting the fuel–fresh gas mixture, wherein the first spark plug (25), the second spark plug (26) and the fuel injector (22) are located between two imaginary parallel planes (27, 28) which are arranged in parallel with a longitudinal central axis (7) of the cylinder (3) and extend at a distance from one another both between the inlet channel mouth openings (14, 15) and between the outlet channel mouth openings (16, 17). The invention also relates to a method for operating an internal combustion engine (1).