Fuel Level Sensor Wiper Assembly for Stable Resistive Card Contact
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Solution Overview
Problem
Existing fuel level sensor assemblies in vehicles, particularly in hybrid electric vehicles, face reliability issues due to permanent deformation and temporary loss of contact between wiper assembly and resistive card, leading to inaccurate readings and potential sensor inoperability.
Innovation Solution
The fuel level sensor assembly incorporates spring-loaded conductive track contacts and a conductive internal plate within a wiper housing, with cylindrical springs urging the contacts toward the resistive card to maintain continuity and reduce deformation, ensuring reliable contact and accurate resistance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If cantilevered contact arms are used in the wiper assembly, then the device complexity is reduced, but the reliability deteriorates due to permanent deformation and temporary loss of contact
Solution Approach 1:
The patent transforms the static cantilevered contact arm into a dynamic spring-loaded system. The contact arm is replaced with a spring mechanism that can dynamically adjust its force output based on contact conditions, allowing the system to adapt to variations in card position and wear while maintaining reliable electrical contact throughout the fuel level measurement range.
Solution Approach 2:
The patent changes the mechanical parameter of the contact mechanism from a rigid cantilever beam to a compliant spring-loaded system. This parameter change allows the contact force to be controlled and maintained within an optimal range, preventing both permanent deformation and temporary loss of contact that plague the cantilevered design.
2Ease of manufacture
If cantilevered contact arms are used, then manufacturing is simpler, but manufacturing precision deteriorates due to permanent deformation during assembly and operation
Solution Approach 1:
The patent applies beforehand cushioning by pre-compressing the spring mechanism during assembly. This pre-compression creates a buffer that absorbs subsequent deformations and stresses during operation, preventing permanent deformation of the contact arm while maintaining dimensional precision throughout the product lifecycle.
3Reliability
If spring-loaded contacts are used, then reliability is improved through maintained contact continuity, but device complexity increases due to additional spring components
Solution Approach 1:
The patent achieves universality by designing the spring-loaded contact mechanism to perform multiple functions simultaneously: it provides continuous contact force, compensates for positioning variations, absorbs mechanical shocks, and maintains electrical connectivity. This multi-functionality justifies the added complexity by eliminating the need for separate adjustment and protection mechanisms.
4Measurement precision
If spring-loaded contacts are used, then measurement precision is improved through consistent contact force, but device complexity increases
Solution Approach 1:
The patent implements self-service through the spring mechanism that automatically maintains optimal contact force without external intervention. The spring's inherent elastic properties provide self-regulating contact pressure that compensates for wear and positioning variations, ensuring consistent measurement precision throughout the fuel level range without requiring manual adjustment or complex control systems.
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 configuration enhances the reliability and accuracy of fuel level detection, reducing the likelihood of sensor failure and customer dissatisfaction by maintaining consistent contact and resistance measurement across the operable range of motion.
Implementation Method 1
at least two cylindrical springs positioned between the at least two conductive track contacts and a conductive internal plate... a spring force is applied to the conductive track contacts, urging the contacts toward the card
Data Source
AI summary
Methods and systems are provided for a fuel delivery system and a fuel level sensor assembly thereof. In one example, a fuel level sensor includes a wiper assembly with spring-loaded wiper contacts. Cylindrical springs are provided between a wiper housing and the contacts to bias the wiper contacts into contact with a resistive card.