Fuel Pump Relay Impact Sensing Integration
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Solution Overview
Problem
The existing inertia switch in vehicles, used to disable the fuel pump during severe crashes, faces challenges in calibration and compatibility with current vehicle structures, and lacks integration with vehicle impact sensing systems, necessitating a replacement that is reliable and compatible with the fuel delivery system without additional systems.
Innovation Solution
The system utilizes the vehicle's restraint control module to sense impacts and employs an electronic fuel pump relay to disable the fuel pump, allowing the powertrain control module to control the fuel pump using pulse width modulation, eliminating the need for a separate inertia switch and integrating with existing fuel delivery systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate inertia switch is used to disable the fuel pump during crashes, then fuel pump cutoff reliability is improved, but device complexity and calibration difficulty increase
Solution Approach 1:
The patent merges the inertia switch functionality into the existing relay control circuitry by integrating an impact sensor directly into the relay assembly. This combines previously separate components (inertia switch, relay, impact sensing) into a unified structure, eliminating the need for a standalone inertia switch while maintaining fuel pump cutoff reliability during crashes.
Solution Approach 2:
The relay assembly is designed to perform multiple functions: normal fuel pump control through electrical signals and crash-induced fuel pump cutoff through impact sensing. The impact sensor integrated into the relay enables the same component to detect both electrical control commands and mechanical impact events, providing universal functionality across different operating conditions.
2Reliability
If a separate inertia switch is implemented, then fuel pump cutoff capability is improved, but ease of manufacture deteriorates due to calibration difficulties
Solution Approach 1:
By combining the impact sensor and relay into a single integrated assembly, the patent eliminates the need for separate calibration of a standalone inertia switch. The integrated design allows the impact threshold to be set during relay manufacturing, simplifying the overall manufacturing process while maintaining reliable fuel pump cutoff capability.
3Reliability
If an inertia switch is added to the fuel delivery system, then impact response reliability is improved, but adaptability to current vehicle structures deteriorates
Solution Approach 1:
The patent merges the impact sensing functionality into the existing relay assembly that is already integrated into the fuel delivery system. This approach adapts to current vehicle structures by utilizing existing mounting locations and electrical connections, eliminating the need for additional packaging space or structural modifications while maintaining reliable impact response.
4Measurement precision
If frequency modulated signals are used for impact sensing, then measurement precision of impact detection is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical impact sensing mechanisms with electronic frequency modulated signal generation and detection. The impact sensor uses electrical signals rather than mechanical linkages, and the frequency modulation provides precise impact detection through electrical signal processing, eliminating the need for complex mechanical calibration while maintaining high measurement precision.
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 enables reliable vehicle impact sensing and fuel control operations without altering the fuel delivery system architecture, ensuring proper fuel pump operation during normal conditions and disabling it only during impacts, improving safety and efficiency.
Implementation Method 1
The present invention includes the added benefit of allowing the powertrain control module to variably control the fuel pump in a mechanical returnless fuel system by using pulse width modulation via the electronic fuel pump relay.
Implementation Method 2
An electronic relay switch is adapted for coupling to the fuel pump motor to selectably energize the fuel pump motor according to a conductive state and a non-conductive state of the electronic relay switch.
Implementation Method 3
The received signal from the restraint control module is preferably a frequency modulated signal which assists in determining the validity of the received signal before deploying the fuel cut-off.
Data Source
AI summary
An apparatus in a mechanical returnless fuel system is provided that includes a fuel pump motor for providing fuel to a powertrain system. A powertrain control module provides an activation signal for activating the fuel pump motor. A restraint control system includes a restraint control module for providing a disabling signal for disabling the fuel pump motor in response to a vehicle impact. An electronic relay switch is adapted for coupling to the fuel pump motor to selectably energize the fuel pump motor according to a conductive state and a non-conductive state of the electronic relay switch. A relay controller packaged with the electronic relay switch is responsive to the activation signal and the disabling signal for selecting the conductive state according to the activation signal when the disabling signal is not present and selecting the nonconductive state when the disabling signal is present.