Electric Motor Driven Fuel Pump for Engine Start Pressure
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Solution Overview
Problem
Direct injection engines face challenges with low fuel pressure during starting events and fuel enrichment due to the limitations of cam-driven fuel pumps, leading to misfire events, poor startability, increased emissions, and decreased fuel economy.
Innovation Solution
An apparatus utilizing an electric motor coupled with a high-pressure fuel pump, which can operate independently of engine cranking to provide supplemental fuel pressure through a reduction gearset or cam and worm gear assembly, ensuring consistent fuel delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a second fuel pump is added to increase fuel pressure during starting events, then fuel pressure is improved, but device complexity and weight increase
Solution Approach 1:
The electric motor of the starting apparatus is made multi-functional by enabling it to both crank the engine and drive the fuel pump. The motor serves dual purposes: as a starting motor during engine cranking and as a driver for the fuel pump to provide supplemental fuel pressure during starting events and fuel enrichment maneuvers, eliminating the need for a separate dedicated fuel pump.
Solution Approach 2:
The functions of the starting motor and the fuel pump driver are merged into a single electric motor. The motor's output shaft is mechanically coupled to both the starting apparatus and the fuel pump, combining what would traditionally be separate components into one integrated unit, thereby reducing overall system complexity and part count.
2Stress or pressure
If a second fuel pump is added to increase fuel pressure during starting events, then fuel pressure is improved, but weight increases
Solution Approach 1:
The functions of the starting motor and the fuel pump driver are merged into a single electric motor. The motor's output shaft is mechanically coupled to both the starting apparatus and the fuel pump, combining what would traditionally be separate components into one integrated unit, thereby reducing overall system complexity and part count.
Solution Approach 2:
The electric motor of the starting apparatus is made multi-functional by enabling it to both crank the engine and drive the fuel pump. The motor serves dual purposes: as a starting motor during engine cranking and as a driver for the fuel pump to provide supplemental fuel pressure during starting events and fuel enrichment maneuvers, eliminating the need for a separate dedicated fuel pump.
3Use of energy by moving object
If gear reduction devices are added to electric motors for normal operating ranges, then motor operation is improved, but device complexity and package space increase
Solution Approach 1:
The system dynamically adjusts the operational mode of the electric motor based on engine conditions. During starting events and fuel enrichment maneuvers when high fuel pressure is needed, the motor operates in fuel pump drive mode. During normal engine operation, the motor transitions to idle or off-state, eliminating the continuous need for gear reduction devices and allowing for a more compact, simplified drivetrain design.
Solution Approach 2:
The operational requirements are segmented into distinct phases: starting events, fuel enrichment maneuvers, and normal operation. During starting and enrichment phases, the motor provides supplemental fuel pressure. During normal operation, the system relies on the primary cam-driven fuel pump, allowing the electric motor-fuel pump assembly to be smaller and simpler without gear reduction devices.
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 effectively addresses low fuel pressure issues by providing reliable high-pressure fuel during engine starting and operation, enhancing startability, reducing emissions, and improving fuel economy, while minimizing additional weight and package space requirements.
Implementation Method 1
an electric motor operative to crank the engine
Implementation Method 2
The electric motor is preferably operable independent from the starting function such that the fuel pump is selectively operable during or independent of engine cranking
Data Source
AI summary
An apparatus for providing pressurized fuel for an engine includes an engine starting apparatus including an electric motor operative to crank the engine and a fuel pump operatively coupled to the electric motor.