Lift Pump Control Using Single Downstream Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current direct injection fuel systems require sensors to control lift pump outlet pressure, increasing system cost and reducing reliability due to the potential degradation of these sensors.
Innovation Solution
A method that operates a lower pressure pump in two modes, adjusting energy supply based on feedback from a single pressure sensor located downstream of the higher pressure pump, eliminating the need for additional sensors and allowing control of lift pump output pressure without a separate pressure transducer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a pressure sensor is installed at the lift pump outlet to control lift pump outlet pressure, then the ability to regulate lift pump output is improved, but system cost increases and reliability decreases due to additional sensor components
Solution Approach 1:
The pressure sensor located downstream of the injection pump serves dual purposes: it monitors pressure for injection pump control and simultaneously provides feedback for lift pump pressure regulation. This multi-functional use of the sensor eliminates the need for a separate lift pump outlet sensor, thereby reducing system cost and improving reliability while maintaining accurate pressure control for both pumps
2Manufacturing precision
If a pressure sensor is installed at the lift pump outlet to control lift pump outlet pressure, then the ability to regulate lift pump output is improved, but system cost increases
Solution Approach 1:
The single pressure sensor downstream of the injection pump performs multiple functions including injection pump pressure control and lift pump pressure regulation feedback. This eliminates the need for additional sensors and control components, simplifying the overall system architecture and reducing cost while maintaining precise pressure control capabilities
3Manufacturing precision
If a pressure sensor is installed at the lift pump outlet to control lift pump outlet pressure, then the ability to regulate lift pump output is improved, but system complexity increases
Solution Approach 1:
The control functions for both the injection pump and lift pump are merged into a single feedback loop using one pressure sensor. The controller integrates both pump control functions, using the same pressure feedback signal to regulate both pumps, thereby reducing system complexity while maintaining precise pressure control
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 approach reduces system complexity and cost while maintaining the ability to regulate lift pump output, improving reliability by using a single pressure sensor to control both pumps, and allows for efficient fuel pressure control in various engine conditions.
Implementation Method 1
a pressure sensor located downstream of the higher pressure pump
Implementation Method 2
one fuel pump (i.e., the lift pump) lifts fuel from a fuel tank and delivers the fuel to a second fuel pump
Implementation Method 3
The second fuel pump increases the fuel pressure to a second pressure so that fuel can be directly injected into a cylinder
Data Source
AI summary
An economical method for controlling a lift pump operating as part of a direct injection fuel system is described. According to the method, at least two distinct operating modes are provided.