Piston-Coupled Pre-Chamber Ignition for Residual Gas Scavenging
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Solution Overview
Problem
Passive pre-chambers in internal combustion engines face challenges with scavenging and ignition issues due to residual gases, especially when exhaust gas recirculation is introduced, leading to mixture misfires and inefficient combustion.
Innovation Solution
The pre-chamber is positioned directly inside the combustion chamber, with a tubular element projecting into it, allowing for optimal scavenging and cooling, and featuring a male-female prismatic coupling with the piston, ensuring minimal heat exchange and efficient flame propagation through lateral openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct injection is used to improve combustion efficiency and reduce emissions, then fuel economy and power output are improved, but the risk of uncontrolled combustion (knocking) increases and the system becomes more complex
Solution Approach 1:
The injection system is divided into two separate injection devices: a direct injection device for efficient combustion and a charge air cooling injection device for controlling combustion stability. This segmentation allows each device to perform its specific function optimally without the complexity of a single integrated system.
Solution Approach 2:
Charge air cooling injection is introduced as an intermediary mechanism that cools the incoming air charge before it enters the combustion chamber. This intermediary approach indirectly controls combustion characteristics and reduces knocking risk without directly modifying the fuel injection system.
2Use of energy by moving object
If direct injection is used to improve combustion efficiency, then fuel economy is improved, but the risk of uncontrolled combustion (knocking) increases
Solution Approach 1:
Charge air cooling injection acts as an intermediary that cools the air charge, thereby indirectly controlling combustion stability and reducing knocking risk while preserving the fuel economy benefits of direct injection.
Solution Approach 2:
The temperature of the charge air is changed through cooling injection, which modifies the combustion characteristics and reduces the tendency for uncontrolled combustion while maintaining efficient fuel combustion.
3Device complexity
If conventional port injection is used to maintain simple system design, then device complexity is reduced, but combustion efficiency and emission reduction are insufficient
Solution Approach 1:
The system segments injection functions into two separate devices: direct injection for efficiency and charge air cooling injection for combustion control. This segmentation achieves superior combustion efficiency and emission reduction compared to conventional port injection.
Solution Approach 2:
The charge air cooling injection device serves multiple functions: it cools the charge air to control combustion stability, prevents knocking, and contributes to emission reduction, making the overall system more effective than simple port injection.
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 enhances scavenging and combustion efficiency by minimizing fluid dynamic losses and reducing combustion time, enabling effective ignition and flame propagation without the need for external fuel injectors or air intakes, similar to active pre-chambers.
Implementation Method 1
direct injection has come into use in order to improve fuel economy and reduce emissions
Implementation Method 2
a liquid is injected onto an intake manifold or an intake port to cool the charge air
Implementation Method 3
Spark ignition internal combustion engine
Data Source
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AI summary
Internal combustion engine with controlled ignition comprising a cylinder (C), a relative piston (P) and a head (H) between which a combustion chamber (CC) is operationally defined. The cylinder and the piston define a first prismatic coupling. The engine also comprises a pre-chamber (PCC) made directly inside the combustion chamber (CC) and a male element (PIN) stably connected to an upper surface (PS) of the piston, so as to penetrate the pre¬ chamber, at least in one portion of the relative motion of the piston in the cylinder. A spark plug is arranged to look out into the pre-chamber.