Ignition Apparatus AC Voltage Ionization Control
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Solution Overview
Problem
The existing ignition apparatus for internal combustion engines faces challenges with increased fuel efficiency demands, leading to higher internal cylinder pressure and voltage requirements, which can result in deep flying-discharge and degradation, necessitating larger and more costly high-frequency high-voltage systems to manage these pressures.
Innovation Solution
An ignition apparatus with an AC voltage application unit and a control system that applies a first AC voltage with a smaller amplitude before ignition, followed by a second AC voltage or its cessation, ionizing gas molecules and diffusing them to reduce the required ignition voltage, thereby preventing deep flying-discharge and avoiding flashover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high voltage signal having high frequency is applied to the ignition plug to generate ions and increase electrode temperature, then the required voltage is lowered and deep flying-discharge is avoided, but the apparatus size increases and manufacturing cost increases
Solution Approach 1:
The patent applies a first AC voltage before the ignition timing to preliminarily ionize gas molecules in the pocket and discharge gap, and to heat the electrode surface. This preliminary action reduces the required ignition voltage and prevents deep flying-discharge without requiring a complex high-frequency high-voltage apparatus during the actual ignition moment.
Solution Approach 2:
The patent divides the voltage application into two distinct periods: a first period before ignition timing when AC voltage is applied to ionize gas and heat the electrode, and a second period when AC voltage is stopped or reduced. This segmentation allows the system to use simple low-voltage AC application rather than complex high-frequency high-voltage signals, reducing apparatus size while maintaining ignitability.
2Reliability
If high voltage signal having high frequency is applied to the ignition plug to generate ions and increase electrode temperature, then the required voltage is lowered and deep flying-discharge is avoided, but manufacturing cost increases
Solution Approach 1:
The patent applies a first AC voltage before the ignition timing to preliminarily ionize gas molecules in the pocket and discharge gap, and to heat the electrode surface. This preliminary action reduces the required ignition voltage and prevents deep flying-discharge without requiring a complex high-frequency high-voltage apparatus during the actual ignition moment.
Solution Approach 2:
The patent divides the voltage application into two distinct periods: a first period before ignition timing when AC voltage is applied to ionize gas and heat the electrode, and a second period when AC voltage is stopped or reduced. This segmentation allows the system to use simple low-voltage AC application rather than complex high-frequency high-voltage signals, reducing apparatus size while maintaining ignitability.
3Reliability
If high voltage is required immediately before the ignition, then discharge can occur, but flashover or corona discharge may be produced before major discharge causing lower ignitability
Solution Approach 1:
The patent applies a first AC voltage before the ignition timing to preliminarily ionize gas molecules in the pocket and discharge gap, and to heat the electrode surface. This preliminary action reduces the required ignition voltage and prevents deep flying-discharge without requiring a complex high-frequency high-voltage apparatus during the actual ignition moment.
Solution Approach 2:
The patent applies AC voltage with amplitude smaller than the required ignition voltage during the first period, and stops or reduces it during the second period. This partial action approach prevents excessive voltage that would cause flashover or corona discharge, while still achieving sufficient ionization and heating to ensure reliable discharge formation.
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 approach enhances ignitability, prevents apparatus size and cost increases, and maintains reliable discharge formation without the need for high-frequency high-voltage signals, thus improving engine performance and reducing manufacturing costs.
Implementation Method 1
an AC electric field is produced in the pocket and the discharge gap of the ignition plug, whereby the gas molecules in the pocket and the discharge gap can be ionized or activated
Implementation Method 2
ultraviolet light, emitted when a part of the activated gaseous molecules return to the ground level, reaches the discharge gap G when the ignition plug is ignited
Data Source
AI summary
An ignition apparatus of an internal combustion engine is provided with an ignition plug, an AC (alternating current) voltage application unit configured to apply AC voltage to the center electrode of the ignition plug, and an application voltage control unit that controls an operation of the AC voltage application unit. The application voltage control unit is configured to control the AC voltage application unit to apply the center electrode with a first AC voltage having an amplitude smaller than that of a required voltage of the ignition plug in a first period which is before an ignition timing, and to apply the center electrode with a second AC voltage having an amplitude smaller than that of the first AC voltage or to stop applying the center electrode with the AC voltage during a second period which is before the ignition timing after the first period has elapsed.