Asymmetric Pre-Chamber Spark Plug Ignition
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Solution Overview
Problem
Conventional pre-chamber spark plugs with rotationally symmetrical openings result in a symmetrical flow, leading to poor convection of the initial flame core and increased risk of pre-ignition, requiring longer electrodes that increase damage volume and wall heat losses.
Innovation Solution
A pre-chamber spark plug with rotationally asymmetrical openings, where the sum of flow cross-sections in one half is greater than the other, creating a tumble-shaped flow that enhances fuel-air mixture convection and ignition stability, reducing pre-ignition risk and wall heat losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rotationally symmetrical openings are used in the pre-chamber spark plug, then the structure is simple and easy to manufacture, but the convection of the initial flame core is poor and pre-ignition risk increases
Solution Approach 1:
The patent applies asymmetry by configuring the openings in the pre-chamber tip with different flow cross-sections - specifically, one opening has a larger flow cross-section than the other openings. This asymmetric configuration creates a tumble flow pattern that enhances convection of the initial flame core toward the openings, improving ignition stability and reducing pre-ignition risk while maintaining manufacturing feasibility
2Ease of manufacture
If rotationally symmetrical openings are used in the pre-chamber spark plug, then the manufacturing is simple, but wall heat losses increase
Solution Approach 1:
The asymmetric opening configuration with one larger opening and two smaller openings creates a tumble flow that directs the flame core away from the pre-chamber walls. This reduces the surface area of the flame that contacts the walls, thereby reducing heat transfer losses to the pre-chamber walls and improving overall combustion efficiency
3Reliability
If longer electrodes are used to compensate for poor flame convection, then ignition reliability improves, but the damage volume increases
Solution Approach 1:
By creating asymmetric flow patterns through the unequal opening cross-sections, the patent achieves strong flame convection that reliably transports the initial flame core to the openings without requiring extended electrode lengths. This maintains ignition reliability while keeping the electrode structure compact and minimizing damage volume
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 tumble-shaped flow improves combustion stability, reduces pre-ignition risk, and increases flare penetration depth, leading to more efficient engine operation with lower residual gas content and reduced damage volume.
Implementation Method 1
at least one electrode device which is arranged at least partially in the pre-chamber. By means of the electrode device, the aforementioned ignition spark can be generated in the pre-chamber
Implementation Method 2
creating a tumble-shaped flow that enhances fuel-air mixture convection and ignition stability
Implementation Method 3
the fuel-air mixture that has flowed into the pre-chamber via the openings can be ignited. By means of the ignition spark, the fuel-air mixture that has flowed into the pre-chamber via the openings can be ignited or ignited and subsequently burned
Data Source
AI summary
A pre-chamber spark plug for a combustion chamber of an internal combustion engine includes a pre-chamber which has a plurality of openings and which is fluidically connectable to the combustion chamber via the plurality of openings. A fuel/air mixture is introducible from the combustion chamber into the pre-chamber via the plurality of openings. Each of the plurality of openings has a respective flow cross section through which the fuel/air mixture is flowable. With respect to an imaginary plane running along an imaginary axis of the pre-chamber and dividing the pre-chamber into a first half and a second half of equal size, a sum of the flow cross sections of first openings disposed in the first half is greater than a sum of the flow cross-sections of second openings disposed in the second half.