Movable Electrode Ignition Unit for Lean Mixtures
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Solution Overview
Problem
Existing ignition units for internal combustion engines face challenges in efficiently igniting lean or less homogeneous mixtures, particularly in the part-load range, due to fixed spark gaps and increased material and energy requirements when using multiple spark gaps or repeated ignitions.
Innovation Solution
An ignition unit with a movable second electrode that sweeps through a predefined area of the combustion chamber, generating multiple ignition sparks between the first, second, and third electrodes, allowing the spark gap to move and pivot, thereby increasing the ignition area without excessive voltage or energy consumption, and using an actuator or piezoceramic to control the electrode movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a fixed spark gap is used between two electrodes, then the ignition unit structure is simple, but the ignition area is limited and cannot effectively ignite lean or less homogeneous mixtures
Solution Approach 1:
The patent makes the electrode arrangement dynamic by allowing the second electrode to move relative to the first electrode along a predefined path. This movement enables the spark gap to sweep through a larger area within the combustion chamber, increasing the effective ignition area without requiring multiple fixed electrodes or complex multi-spark systems.
Solution Approach 2:
The ignition area is segmented into multiple positions along the movement path of the second electrode. As the electrode moves, it creates a sequence of spark gaps at different locations, effectively dividing the ignition task across multiple spatial positions while using a single movable electrode pair.
2Reliability
If multiple ignition spark gaps are provided within a combustion chamber, then the probability of successful ignition increases, but the material and electrical energy requirements increase
Solution Approach 1:
Instead of providing multiple simultaneous static spark gaps that would require multiple electrode pairs and high energy input, the patent uses a single dynamic spark gap that moves through different positions. This allows the system to sequentially access multiple ignition locations with a single electrode pair, reducing material and energy requirements while maintaining high ignition reliability.
Solution Approach 2:
The movable electrode generates ignition sparks at different positions along its path in a periodic sequence. The electrode moves through a predefined area, creating sparks at various locations over time, which increases the probability of successful ignition without requiring all spark gaps to be active simultaneously, thus reducing energy consumption.
3Area of stationary object
If the second electrode is made movable to sweep through a predefined area, then the ignition area increases, but the device complexity increases due to actuator requirements
Solution Approach 1:
The patent introduces a movable second electrode that can be displaced, rotated, or pivoted relative to the first electrode using an actuator. This dynamic configuration allows the spark gap to sweep through a predefined area of the combustion chamber, significantly increasing the ignition area coverage while maintaining a relatively simple overall structure compared to multiple fixed electrode systems.
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 design enhances the probability of successful ignition by increasing the area traversed by the ignition spark, reduces the required ignition voltage, minimizes energy consumption, and reduces spark erosion by allowing the spark to migrate and merge, thus improving ignition reliability and efficiency.
Implementation Method 1
an actuator (or 'motor'), which is an optional part of the ignition unit and moves the second electrode according to the electromagnetic principle
Implementation Method 2
via a piezoceramic
Implementation Method 3
Electrical energy, often temporarily stored by means of an inductance, breaks through the combustion chamber volume between two electrodes, causing the ignitable mixture in the combustion chamber to be ignited
Implementation Method 4
Electrical energy, often temporarily stored by means of an inductance
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5aII
AI summary
The invention relates to an ignition device for a combustion chamber of an internal combustion engine, comprising a first electrode and a second electrode. The second electrode can be moved by means of an actuator. The ignition device is designed to produce a first ignition spark when contact between the first electrode and the second electrode is broken. For this purpose, the second electrode is removed from the first electrode. According to the invention, a third electrode is provided, which has a distance from the first electrode. A second ignition spark can be additionally produced by means of the third electrode by removing the second electrode from the two other electrodes. By means of the three electrodes, the ignition unit is designed to let the two ignition sparks to pass through a volume formed between the electrodes in a direction perpendicular to the longitudinal extension of the ignition sparks in the course of the motion of the second electrode.