Ignition Control Apparatus Abnormality Recovery and Heat Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ignition devices for internal combustion engines fail to effectively detect when a discharge control circuit or unit has returned to a normal state after an abnormality, leading to continued fail-safe processes that prevent the utilization of restored devices.
Innovation Solution
A control apparatus that includes an ignition device and an electronic control unit, which determines abnormalities in the discharge control unit and circuit, avoids control over discharge current during abnormalities, and checks for a return to normal by controlling the discharge current to a minimum value, allowing detection of the normal state and minimizing excessive heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fail-safe process is continued after an abnormality is detected, then the system ensures safety by avoiding control over discharge current, but the system cannot detect when the discharge control circuit or unit has returned to a normal state, leading to continued unnecessary fail-safe operation
Solution Approach 1:
The patent implements a feedback mechanism where the ECU monitors the discharge current value during fail-safe operation and compares it against a threshold. When the discharge current falls below the threshold (indicating normal operation has resumed), the system automatically cancels the fail-safe process and restores normal control. This feedback loop enables the system to detect recovery from abnormality and transition back to normal operation.
2Productivity
If the discharge control unit continues to operate after an abnormality, then the system maintains normal control functions, but excessive heat is generated and the system risks further damage
Solution Approach 1:
The patent applies preliminary action by detecting abnormalities in the discharge control circuit or unit before they lead to excessive heat generation or system failure. When an abnormality is detected (such as discharge current exceeding a threshold), the ECU immediately cancels control over the discharge current, preventing the temperature from rising to dangerous levels and avoiding further damage to the system.
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
Enables the detection of a discharge control unit or circuit's return to a normal state, preventing excessive heat and ensuring the proper utilization of restored ignition devices, while maintaining ignitability and reducing temperature risks.
Implementation Method 1
an ignition coil connected to the spark plug
Implementation Method 2
a discharge control circuit that retains discharge current after a start of discharging of the spark plug
Data Source
AI summary
An ECU outputs an ignition signal and a discharge waveform control signal. An ignition device closes an ignition switching element in a period during which the ignition signal is input. After a stop of the input of the ignition signal and in a period of input of the discharge waveform control signal, the ignition device controls current flowing through a primary coil to a discharge current command value that is determined by the discharge waveform control signal by opening or closing a control switching element. A discharge control unit determines whether there is an abnormality. When it is determined that there is an abnormality, the ECU avoids control executed by the discharge control unit, and causes the discharge control unit to execute control during times of low-rotation and low-load operation of an internal combustion engine in order to determine whether the discharge control unit has returned to a normal state.