Ignition Device Non-Overlapping Switching Logic
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Solution Overview
Problem
Existing ignition devices for internal combustion engines that supply electrical energy from two ignition coils to a single spark plug face complexity in on/off switching due to overlapping periods of switching units, leading to unstable discharge and potential electrode damage.
Innovation Solution
An ignition device with a first switching unit for starting spark discharge and a booster circuit to accumulate energy, and a second switching unit for maintaining continuous spark discharge, allowing for non-overlapping switching periods and stable discharge current, using two ignition coils with specific specifications for main ignition and continuous spark discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If on/off switching of two switching units is performed alternately with non-overlapping on-periods, then stable discharge state with no interrupted discharge can be maintained, but control logic becomes complicated and calculation load increases
Solution Approach 1:
The patent divides the ignition system into two independent ignition coils (first ignition coil and second ignition coil), each with its own switching unit. This segmentation allows each switching unit to operate independently without complex coordination, as each coil can generate spark discharge separately. The control logic is simplified by treating them as independent units rather than requiring complex overlapping/non-overlapping period management.
Solution Approach 2:
The patent changes the operational parameters of the two ignition coils by assigning different specifications to each coil. The first ignition coil is designed with higher inductance for main ignition, while the second ignition coil has lower inductance for continuous spark discharge. This parameter differentiation allows each switching unit to operate with optimized timing characteristics, simplifying the overall control logic.
2Reliability
If on-periods of first and second switching units are overlapped, then discharge current decreases rapidly and spark discharge cannot be maintained, but avoiding overlap requires high accuracy switching
Solution Approach 1:
By segmenting the ignition function into two separate coils with dedicated switching units, the system eliminates the need for precise overlapping control. Each switching unit operates independently with its own optimized timing, removing the requirement for high-precision synchronization between the two units.
Solution Approach 2:
The patent employs partial action by having the first switching unit operate only during the main ignition phase (non-overlapping with second unit), while the second switching unit handles the continuous spark discharge phase. This partial operational division allows each unit to function within optimized parameters without requiring precise coordination.
3Object-affected harmful factors
If Off-periods of first and second switching units are overlapped, then discharge timings overlap causing discharge current to increase rapidly and electrode damage occurs, but preventing overlap increases control complexity
Solution Approach 1:
The patent segments the switching control into two independent units, each managing its own ignition coil without requiring coordination with the other. This eliminates the risk of overlapping off-periods causing discharge timing conflicts, as each unit operates autonomously with independently controlled timing.
Solution Approach 2:
The patent introduces an intermediary approach by using two separate ignition coils as mediators between the battery and the spark plug. Each coil acts as an independent intermediate stage that can be controlled separately, preventing direct interaction between the switching units that would cause harmful overlap effects.
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 reduces complexity in switching logic, maintains stable discharge current, and prevents electrode wear by ensuring non-overlapping switching periods and optimizing coil specifications for ignitability and discharge current.
Implementation Method 1
a first switching unit for turning on/off a power supply to a primary coil, which is one of the ignition coils, from an on-vehicle battery
Implementation Method 2
the booster circuit boosts a voltage of the on-vehicle battery and accumulates the electrical energy
Implementation Method 3
the second switching unit superimposes a current having the same direction as the spark discharge generated by turning on/off the first switching unit between the electrodes of the spark plug by supplying the electrical energy accumulated in the booster circuit into the primary coil of the second ignition coil
Data Source
AI summary
According to an ignition device, a first switching unit applies a voltage between electrodes of by spark plug by turning on/off energization from an on-vehicle battery to a primary coil. Further, a second switching unit applies a voltage having the same direction as a spark discharge generated by turning on/off the first switching unit between the electrodes of the spark plug by supplying electrical energy accumulated in a booster circuit into a primary coil. Accordingly, it is possible to greatly reduce a complexity of the on/off switching of the first and second switching units compared to a conventional technology.