Vehicle Battery Sensor Flat Resistance Element and Contact Design
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Solution Overview
Problem
Existing motor vehicle battery sensors face challenges in manufacturing complexity and accuracy due to the need for precise voltage measurement across shunts, which are affected by thermal stresses and material spatter during welding, leading to increased production costs and potential measurement inaccuracies.
Innovation Solution
A motor vehicle battery sensor with a flat resistance element and spatially separate electrical contacts arranged on its surface, where the contacts serve as spacers and are connected to the integrated circuit via ultrasonic welding, eliminating the need for milling and reducing thermal stresses, while allowing for accurate temperature sensing and improved mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is used to connect resistance piece and terminal pieces, then mechanical strength is improved, but material spatter changes conductivity and welding introduces thermal stresses
Solution Approach 1:
The patent introduces a copper foil layer as an intermediary between the resistance piece and terminal pieces. This foil acts as a buffer that prevents direct welding contact, thereby avoiding material spatter on the resistance piece and reducing thermal stress transmission. The copper foil is specifically designed to be welded to the terminal pieces while remaining non-contacting or minimally contacting with the resistance piece, thus preserving the resistance piece's conductivity accuracy.
2Reliability
If resistance piece is milled to form depression, then integration circuit contact prevention is improved, but manufacturing complexity increases
Solution Approach 1:
The patent extracts the contact prevention function from the resistance piece itself by introducing separate insulating elements and positioning structures. Instead of modifying the resistance piece geometry through milling, the solution uses dedicated insulating components that physically prevent integration circuit contact while keeping the resistance piece geometry simple and easy to manufacture.
3Strength
If friction welding is used to connect flat parts, then joining strength is improved, but welding material spatter onto resistance piece changes conductivity
Solution Approach 1:
The copper foil serves as a mediator between the friction welding process and the resistance piece. The foil is positioned to receive the welding process (being welded to terminal pieces) while protecting the resistance piece from spatter. This intermediary approach maintains the benefits of friction welding for joining strength while preserving the electrical conductivity accuracy of the resistance piece.
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 design simplifies manufacturing, reduces production costs, and enhances measurement accuracy by preventing material spatter and thermal stresses, while enabling a larger integrated circuit size and improved mechanical support for the sensor.
Implementation Method 1
the voltage drop across the shunt precisely... measure the voltage drop across the shunt precisely... measure the voltage drop across the resistance element to determine current flow
Implementation Method 2
at least the physical quantities of current, voltage and/or temperature of the resistance element can be evaluated... measures not only the current in the energy conductor of the battery but also the voltage and/or the temperature
Data Source
Figure 1a~1c
Figure 2~4c
Figure 5~6
AI summary
The invention relates to a motor vehicle battery sensor element comprising a resistor element (2) and at least two electric contacts (16) that are situated on the resistor element and are at a distance from one another. The motor vehicle battery sensor element provides good mechanical characteristics with low production costs, if the resistor element is designed as a planar part with a level surface (10) and if the contacts lie flat on the surface of the resistor element.