Fuel Injection Control for Low Load Pressure Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In dual injection internal combustion engines, reducing the fuel pressure of direct injection injectors quickly in low load conditions is challenging due to the high fuel pressure maintained by both port and direct injection injectors, leading to variations in injection amounts and inefficient fuel combustion during idling.
Innovation Solution
A fuel injection control system that dynamically adjusts the fuel pressure by stopping MPI injection and setting the GDI injection amount to the target fuel injection amount when the engine is in a low load condition, using an engine control module to control the high-pressure fuel pump and manage fuel pressures in the GDI fuel tube, allowing for precise fuel injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If both port injector and direct injection injector are operated simultaneously to supply required fuel amount, then fuel supply quantity is sufficient, but fuel pressure in direct injection injector cannot be reduced quickly leading to injection amount variations
Solution Approach 1:
The fuel injection system is segmented into two independent injection paths: port injection and direct injection. The control device can independently control each injector, allowing selective operation where only the direct injection injector operates in low load conditions, enabling precise fuel pressure control and accurate injection amounts while maintaining sufficient fuel supply capability when both are needed
Solution Approach 2:
The control device dynamically switches between different injection modes based on engine operating conditions (load). In low load conditions, only direct injection operates with reduced fuel pressure for precise control. In high load conditions, both port and direct injection operate simultaneously to maximize fuel supply. This dynamic adaptation resolves the contradiction by adjusting the system configuration according to real-time demands
2Quantity of substance
If fuel pressure is maintained high in direct injection injector for sufficient fuel supply, then fuel availability is ensured, but injection amount variations increase and combustion efficiency decreases
Solution Approach 1:
The control device changes the fuel pressure parameter dynamically based on engine load conditions. In low load conditions, fuel pressure in the direct injection injector is reduced to a lower level, which stabilizes the injection process and reduces injection amount variations. In high load conditions, fuel pressure is maintained at higher levels to ensure sufficient fuel supply. This parameter adaptation ensures both fuel availability and injection control reliability under different operating conditions
3Quantity of substance
If port injector injection is continued to supply fuel, then fuel supply amount is maintained, but fuel pressure reduction in direct injection injector is delayed causing injection variations
Solution Approach 1:
The control device extracts the port injection function from the combined injection system in low load conditions, operating only the direct injection injector. This separation allows the direct injection system to independently control fuel pressure without being constrained by port injection requirements, enabling rapid fuel pressure reduction and stable injection control while still meeting the reduced fuel supply demands of low load operation
Data Source
Figure 1
Figure 2
Figure 3A~3F
AI summary
An internal combustion engine includes a port injector that injects fuel into an intake port and a direct injection injector that injects fuel directly into a combustion chamber. When the internal combustion engine is in a low load condition while requiring fuel injection, a controller stops fuel injection through the port injector so that an entire required fuel injection amount is injected through the direct injection injector. As a result of this processing, the fuel pressure of the direct injection injector is reduced quickly in the low load condition.