Pre-combustion Chamber Segmentation for Tool-Free Maintenance

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Solution Overview

Problem

Existing ignition devices for internal combustion engines with pre-combustion chambers require complex tooling for assembly and disassembly, and there is a risk of damaging components during maintenance, especially when the pre-combustion chamber parts wear out.

Innovation Solution

The ignition device is designed with first and second pre-combustion chamber parts that can be pre-assembled using engageable threads or a bayonet configuration, allowing for easy assembly and disassembly without specialized tools, and featuring a positioning device to inhibit rotational movement, ensuring secure axial alignment and preventing damage during maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional ignition devices are used with pre-combustion chambers, then the engine can operate with gaseous fuel, but complex tooling is required for assembly and disassembly

Engineering Contradiction:
Improveassembly and disassemblyVSAvoidtooling complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The pre-combustion chamber is divided into two separate parts: a first pre-combustion chamber part that remains in the engine and a second pre-combustion chamber part that can be removed. This segmentation allows the removable part to be easily detached without requiring complex tooling, while the remaining part stays securely installed in the engine.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second pre-combustion chamber part is extracted as a separate removable component from the engine system. This extracted part can be easily removed and replaced by the user without requiring specialized tools or complex disassembly procedures, significantly improving ease of operation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of repair

If pre-combustion chamber parts are made removable for easy maintenance, then component reuse is enabled, but rotational misalignment may occur during assembly

Engineering Contradiction:
Improvemaintenance accessibilityVSAvoidaxial alignment
Core Design Contradiction:
Ease of repairVSManufacturing precision

Solution Approach 1:

The positioning device introduces asymmetric features to the otherwise symmetric pre-combustion chamber parts. The locking element has a specific shape that corresponds to a matching feature on the other part, creating an asymmetric relationship that ensures correct rotational orientation and prevents misalignment during assembly.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The positioning device with locking element automatically self-aligns the two pre-combustion chamber parts when assembled. The locking element engages with its corresponding feature to automatically establish the correct axial alignment and rotational orientation, eliminating the need for precise manual alignment during maintenance operations.

Inventive Principle:
Principle #25Self-service

3Strength

If the pre-combustion chamber is designed as a single integrated part, then structural integrity is maintained, but damage risk during maintenance increases

Engineering Contradiction:
Improvestructural integrityVSAvoiddamage risk during maintenance
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The pre-combustion chamber is segmented into two parts, with the second part being removable. This allows the critical first part that remains in the engine to maintain its structural integrity, while the removable second part can be safely detached and replaced without risking damage to the permanently installed components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vulnerable or wear-prone second pre-combustion chamber part is extracted as a separate removable component. This extraction allows users to remove and replace only the necessary part without risking damage to the main engine structure or the permanently installed first pre-combustion chamber part.

Inventive Principle:
Principle #2Taking out (Extraction)

4Manufacturing precision

If engagement features are added to prevent rotational movement, then axial alignment is secured, but device complexity increases

Engineering Contradiction:
Improveaxial alignmentVSAvoidengagement features
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The positioning device uses simple asymmetric features (such as a protruding locking element and its corresponding recess) that are easy to manufacture and implement. These asymmetric features effectively prevent rotational misalignment without requiring complex engagement mechanisms, maintaining simplicity while ensuring precise axial alignment.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2977582B1Ignition device with pre-combustion chamber
Publication Date: 2018.03.28 CATERPILLAR ENERGY SOLUTIONS
  • EP2977582B1 patent drawingFigure 1
  • EP2977582B1 patent drawingFigure 2
  • EP2977582B1 patent drawingFigure 3

AI summary

The present disclosure relates to an ignition device (60) with a pre-combustion chamber (68) of an internal combustion engine (10) having a plurality of cylinders (14) each defining a main combustion chamber (26). The ignition device (60) may comprise a first pre-combustion chamber part (70) configured to at least partially accommodate a spark plug (62). The ignition device (60) may further comprise a second pre-combustion chamber part (80) defining at least a portion of the pre-combustion chamber (68) and including at least one orifice (83) configured to be fluidly connected to the main combustion chamber (26). The second pre-combustion chamber part (80) being detachably mountable to the first pre-combustion chamber part (70), such that the first and second pre-combustion chamber parts (70, 80) are axially secured to one another and rotable with respect to one another.