Fuel Injection Control Device Hysteresis Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines of the cylinder-injection type face variations in injection amounts during compression and expansion strokes, leading to increased particulate matter (PM) emissions and accidental fires due to hysteresis in drive current profiles.
Innovation Solution
An injection control device that sets the drive current of the fuel injection valve using a drive current profile with no hysteresis in change characteristics with respect to fuel pressure, specifically for compression and expansion stroke injections, to stabilize the injection amount and prevent PM emission and accidental fires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a drive current profile with hysteresis is used to prevent frequent drive current changes with fuel pressure variations, then the drive current stability is improved, but the injection amount variation increases causing PM emission increase and accidental fire risk
Solution Approach 1:
The patent segments the drive current profile into two distinct modes: one with hysteresis for intake stroke injection and one without hysteresis for compression/expansion stroke injection. This segmentation allows the system to apply different control strategies for different injection types, resolving the contradiction by eliminating hysteresis-induced variation for compression and expansion strokes while maintaining it for intake strokes where it provides stability.
Solution Approach 2:
The patent applies local quality by making the hysteresis characteristic conditional rather than universal. The drive current profile has hysteresis only in specific operating conditions (intake stroke injection) where it is beneficial, while eliminating hysteresis in other conditions (compression and expansion stroke injection) where it causes harm. This localized application of hysteresis resolves the contradiction.
2Reliability
If the drive current is increased to ensure reliable fuel injection valve opening at high fuel pressure, then the injection reliability is improved, but the injection amount variation due to hysteresis causes PM emission increase
Solution Approach 1:
The patent makes the drive current profile dynamic by selecting between two different profiles based on the injection type. For compression and expansion stroke injections, the system dynamically switches to a profile without hysteresis, eliminating the source of injection amount variation and PM emission while maintaining reliable valve opening through appropriate drive current levels.
Data Source
AI summary
A injection control device for an internal combustion engine includes a fuel injection valve directly injecting a fuel into a cylinder of the internal combustion engine, and a drive current setting unit setting a drive current of the fuel injection valve according to a fuel pressure that is a pressure of the fuel supplied to the fuel injection valve, using a drive current profile specifying a relation between the fuel pressure and the drive current. When a compression stroke injection injecting the fuel in a compression stroke or an expansion stroke injection injecting the fuel in an expansion stroke is executed, the drive current setting unit sets the drive current using a predetermined profile having no hysteresis in change characteristics of the drive current with respect to the fuel pressure in a fuel pressure region of the compression stroke injection or the expansion stroke injection, as the drive current profile.