Hybrid Fuel Injection System with Decoupled High-Pressure Pump
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Combined port fuel injection and direct fuel injection systems face efficiency limitations due to parasitic losses associated with the high-pressure fuel pump required for direct fuel injectors, particularly at partial load engine operations.
Innovation Solution
A fuel injection system that includes a low-pressure fuel pump and a high-pressure fuel pump, with a lost motion lifter that decouples the high-pressure fuel pump from the engine during partial load operations, allowing only port fuel injection to occur, thereby reducing parasitic losses and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a high-pressure fuel pump is used for direct fuel injection, then fuel injection pressure is improved, but parasitic losses increase
Solution Approach 1:
The patent applies the dynamics principle by making the high-pressure fuel pump's engagement dynamic rather than static. The pump is selectively coupled to the engine only when direct fuel injection is required (e.g., at high load conditions), and decoupled when not needed. This allows the system to have high fuel injection pressure when required while minimizing parasitic losses during normal operation when the pump is disengaged from the engine's camshaft drive.
2Temperature
If direct fuel injection is used, then compression ratio is improved, but air-fuel mixing is worsened
Solution Approach 1:
The patent merges port fuel injection and direct fuel injection systems into a hybrid configuration. The port fuel injectors pre-mix fuel with air in the intake manifold, providing good air-fuel mixing. The direct fuel injectors then inject additional fuel directly into the cylinder for charge cooling and high compression ratio operation. This combination allows the system to achieve both good mixing (from port injection) and high compression ratio capability (from direct injection).
3Productivity
If combined port fuel injection and direct fuel injection is used, then engine efficiency is improved, but parasitic losses from dual fuel pumps increase
Solution Approach 1:
The patent uses dynamics to selectively engage the high-pressure fuel pump only when direct fuel injection is required for high-efficiency operation. During normal partial-load operation, the system uses only port fuel injection with the low-pressure pump, eliminating the parasitic losses from the high-pressure pump. When high load conditions require direct injection for maximum efficiency, the pump is dynamically coupled to the engine via the lost motion lifter mechanism.
Solution Approach 2:
The patent extracts the high-pressure fuel pump from continuous operation and isolates it to only operate when directly needed. The lost motion lifter mechanism allows the pump to be physically decoupled from the engine's camshaft drive during conditions when direct injection is not required, effectively removing the source of parasitic losses from the system during normal operation.
4Power
If high-pressure fuel pump is continuously operated, then direct fuel injection performance is improved, but fuel pump efficiency is worsened
Solution Approach 1:
The patent applies periodic action by operating the high-pressure fuel pump only during specific periods when direct fuel injection is required (high load conditions), rather than continuously. The lost motion lifter mechanism enables the pump to be periodically engaged and disengaged based on engine operating conditions, maximizing direct injection performance when needed while minimizing energy consumption during normal operation.
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 solution enhances engine efficiency by eliminating parasitic losses and reducing carbon monoxide emissions at partial load operations while enabling direct fuel injection for full load operations, allowing for higher compression ratios and improved engine performance.
Implementation Method 1
a lost motion lifter selectively coupling the high-pressure fuel pump to the engine. The high-pressure fuel pump supplies fuel to the at least one direct fuel injector when the high-pressure fuel pump is coupled to the engine by the lost motion lifter in response to full load operation of the engine. The lost motion lifter selectively decouples the high-pressure fuel pump from the engine in response to partial load operation of the engine
Implementation Method 2
a high-pressure fuel pump for supplying fuel at a second pressure. The second pressure is greater than the first pressure, meaning that the fuel pressure supplied by the high-pressure fuel pump is greater than the fuel pressure supplied by the low-pressure fuel pump
Data Source
AI summary
A system and method for injecting fuel into an engine is provided where a low-pressure fuel pump is connected in fluid communication with at least one port fuel injector and a high-pressure fuel pump is connected in fluid communication with at least one direct fuel injector. The port fuel injector is disposed along an intake path of the engine and the direct fuel injector is disposed adjacent a cylinder of the engine. A lost motion lifter selectively couples the high-pressure fuel pump and the engine. A pump deactivation module switches the lost motion lifter to selectively deactivate the high-pressure fuel pump from the engine in response to partial load operation of the engine. The pump deactivation module may additionally switch the port fuel injector to an activated state and the direct fuel injector to a deactivated state.