Engine Fuel Injection Controller Dynamic Peak Current Guard
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing controllers for internal combustion engines often set peak current values for in-cylinder injection valves regardless of whether the fuel pressure has converged to the target pressure, leading to excessive current flow and increased thermal ratings for the drive circuit.
Innovation Solution
A controller with a fuel pressure control processor, instruction value calculator, upper limit guard processor, convergence determination processor, and decreasing processor to dynamically adjust the peak current value based on fuel pressure convergence, ensuring efficient fuel injection while minimizing excessive current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the peak current value is increased to ensure reliable fuel injection at high fuel pressure, then the reliability of fuel injection is improved, but the thermal rating requirement of the drive circuit increases
Solution Approach 1:
The patent applies dynamics by making the peak current value adjustable rather than fixed. The control device dynamically changes the peak current value based on detected fuel pressure conditions, allowing the system to use higher currents only when necessary for reliable injection while using lower currents during normal operation, thereby reducing overall thermal load on the drive circuit.
Solution Approach 2:
The patent changes the parameter of peak current value based on fuel pressure detection. When fuel pressure is within a predetermined range, a lower peak current value is used; when fuel pressure exceeds this range, a higher peak current value is applied. This parameter adaptation ensures reliable fuel injection only when needed while minimizing thermal rating requirements during normal conditions.
2Device complexity
If a fixed upper limit guard value is used for peak current, then the control system is simple, but the peak current may be excessively high when fuel pressure is stable
Solution Approach 1:
The patent implements feedback by continuously detecting fuel pressure and using this information to adjust the peak current value. The control device monitors fuel pressure conditions and provides feedback to modify the peak current setting, ensuring that current flow is optimized based on actual operating conditions rather than using a fixed conservative limit.
Solution Approach 2:
The upper limit guard value for peak current is made dynamic rather than fixed. The control device adjusts this limit based on detected fuel pressure, allowing the system to reduce current flow when fuel pressure is stable and within acceptable ranges, thereby reducing energy loss while maintaining injection reliability when needed.
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
The solution reduces situations where the peak current becomes excessively large, enabling consistent fuel injection while lowering the thermal rating of the drive circuit by adjusting the upper limit guard value based on fuel pressure convergence.
Implementation Method 1
Each in-cylinder injection valve includes a coil that opens the valve when energized to inject fuel into a corresponding combustion chamber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A controller (60) for an internal combustion engine (10) including a fuel pressure control processor that controls a fuel pressure at a target fuel pressure, an instruction value calculating processor that calculates a peak instruction value, an upper limit guard processor that executes a guard process on the peak instruction value, an energizing processor that energizes the coil based on the peak instruction value that has undergone the guard process, a convergence determination processor that determines whether or not the detected fuel pressure has converged on the target fuel pressure, and a decreasing processor that decreases the upper limit guard value to a lower value when the fuel pressure has converged on the target fuel pressure than when the fuel pressure has not converged on the target fuel pressure.