Additive-Manufactured Current Sensor Shunt With Low Contact Resistance
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Solution Overview
Problem
Existing electrical shunt manufacturing methods face limitations in material compatibility, contact resistance, and geometric optimization, requiring complex assembly processes and additional machining steps for calibration.
Innovation Solution
A method involving additive manufacturing of a resistive element within a non-through cavity in a metal substrate, followed by annealing and substrate removal to form electrodes, allowing for a wider range of materials and reduced contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional manufacturing processes (brazing, welding, mechanical assembly) are used to assemble resistive element and electrodes, then material compatibility and electrical conductivity can be ensured, but geometric and dimensional optimization is limited and contact resistance cannot be sufficiently reduced
Solution Approach 1:
The patent merges the resistive element and electrodes into a single monolithic component manufactured by additive manufacturing. This eliminates the traditional assembly process (brazing, welding, mechanical fastening) and creates direct metal continuity, reducing contact resistance to near-zero values while enabling complex geometric optimizations that would be impossible with separate components.
Solution Approach 2:
The additive manufacturing process enables the resistive element-electrode assembly to serve multiple functions simultaneously: it provides the calibrated resistance function, acts as the electrode structure, creates optimized current paths, and enables complex geometries for thermal management and mechanical stability, all in a single integrated component.
2Reliability
If copper-based alloys are used for resistive element to ensure electrical characteristics, then measurement accuracy and reliability are guaranteed, but material selection is limited and contact resistance with electrodes cannot be minimized
Solution Approach 1:
The patent changes the material parameter from traditional copper-based alloys to aluminum or aluminum-based alloys for the resistive element. This material substitution, enabled by additive manufacturing, maintains measurement accuracy while allowing optimization of electrical and thermal properties through direct digital manufacturing, reducing contact resistance at the aluminum-copper electrode interface.
Solution Approach 2:
The patent employs composite material strategies where aluminum-based resistive elements are integrated with copper-based electrodes, creating a heterogeneous structure that optimizes the balance between electrical conductivity, thermal management, and mechanical properties, with the additive manufacturing process enabling metallurgical bonding between dissimilar materials.
3Manufacturing precision
If localized machining is used for calibration of resistive element, then resistance value can be adjusted, but manufacturing complexity increases and production time is extended
Solution Approach 1:
The patent performs resistance calibration during the additive manufacturing process itself, before the component is completed and removed from the build platform. The resistive element is manufactured with its final calibrated resistance value directly embedded in the digital model, eliminating post-manufacturing machining operations and enabling immediate use without additional calibration steps.
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
Enables the use of lighter materials like aluminum and improves mechanical and electrical properties by eliminating the need for post-manufacturing machining, enhancing the shunt's performance and versatility.
Implementation Method 1
make, by additive manufacturing, a resistive element in said cavity
Implementation Method 2
anneal the assembly thus obtained
Data Source
Figure 1~2
Figure 3a~3f
Figure 4a~4b
AI summary
The invention relates to a method for manufacturing an electric current sensor (SHE) comprising the following steps: a) providing a substrate (SBT) made of metal or metal alloy, b) making a non-through cavity (CVT) in said substrate such that said cavity separates the substrate into two zones (Z1, Z2), c) making, by additive manufacturing, a resistive element (ER) in said cavity (CVT), d) annealing the assembly thus obtained, e) removing a part of the substrate (SBT) to leave only the resistive element (ER) between the two zones (Z1, Z2) of the substrate, and f) defining, within each zone (Z1, Z2), a connection terminal (BCE1, BCE2) to obtain electrodes (PEL, DEL).