Ignition Coil Magnetic Saturation Prevention
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Solution Overview
Problem
The existing ignition coil apparatus for internal combustion engines, particularly the full transistor type, faces challenges in improving ignition performance across the entire engine rotation range due to magnetic saturation in the center core, which limits the effective inductance and primary current, especially in low rotation number regions.
Innovation Solution
The ignition coil apparatus includes a center core with magnets arranged on opposite end faces to counteract magnetic flux lines, and a primary coil with a resistance value between 0.8 Ω and 1.2 Ω, which enhances ignition performance without increasing the cross-sectional area or number of turns, thereby preventing magnetic saturation and maintaining efficient energy accumulation and release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cross-sectional area of the center core is increased to improve ignition performance in low rotation number regions, then the effective inductance increases, but the ignition coil cannot fit within the elongated plug hole
Solution Approach 1:
The patent changes the magnetic properties of the center core by arranging magnets on its end faces to apply magnetic force in the opposite direction to magnetic flux lines. This parameter change in magnetic field distribution prevents magnetic saturation without increasing the physical cross-sectional area, allowing the ignition coil to maintain improved ignition performance while fitting within the existing plug hole dimensions.
2Productivity
If the resistance value of the primary coil is reduced to supply larger primary current and improve ignition performance, then the rising speed of primary current increases, but magnetic saturation occurs in the center core reducing effective inductance
Solution Approach 1:
The patent applies preliminary anti-action by arranging magnets on the end faces of the center core to generate magnetic force in the opposite direction to the magnetic flux lines before magnetic saturation can occur. This counteracting magnetic force prevents the magnetic core from reaching saturation state, allowing the primary coil to operate at higher currents with improved rising speed while maintaining effective inductance throughout the operating range.
3Reliability
If magnets are arranged on the center core to prevent magnetic saturation, then ignition performance improves across the entire rotation range, but the device complexity increases
Solution Approach 1:
The magnets arranged on the center core serve multiple functions: they prevent magnetic saturation in the center core, maintain effective inductance across the entire rotation range, and enable the ignition coil to operate efficiently without requiring additional current limiting circuits or increasing the cross-sectional area. This multi-functionality improves ignition performance while avoiding proportional increases in device complexity.
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 improves ignition performance across the entire engine rotation range, from 0 to 12,000 rpm, while keeping electric power consumption equivalent to conventional systems, and allows the ignition coil to fit within existing plug holes without needing additional current limiting circuits, thus balancing performance and cost.
Implementation Method 1
A magnet is arranged on at least one of opposite end faces of the center core for applying a magnetic force thereto in a direction opposite to the direction of magnetic flux lines generated when a primary current is supplied to the primary coil
Implementation Method 2
magnetic flux lines generated when a primary current is supplied to the primary coil
Data Source
AI summary
An ignition coil apparatus for an internal combustion engine can improve the ignition performance of the engine in an entire rotation range. The ignition coil apparatus is arranged in a plug hole formed in the engine, and includes a case (1), a center core (2) arranged on a central axis of the case (1), and a primary coil (3) and a secondary coil (4) both arranged on an outer periphery of the center core (2). Magnets (20) are arranged on the opposite end faces, respectively, of the center core (2) for applying a magnetic force thereto in a direction opposite to the direction of magnetic flux lines generated when a primary current (i1) is supplied to the primary coil (3), and the primary coil (3) has a resistance, an upper limit value of which is 1.2 Ω.