Shunt Resistor Bonding Strength via Flange Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional shunt resistors used in high-voltage applications, such as electric vehicles, suffer from insufficient bonding strength due to reduced welding area, which affects the accuracy and reliability of current measurements.
Innovation Solution
The shunt resistor design includes a pair of bases with recessed holes and a measurement terminal with a shaft and flange part, where the flange part is welded on the lateral periphery, increasing the welding area and load capacity, and the shaft part is inserted into a smaller recessed hole, enhancing axial and thrust direction load capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the measurement terminal is surface-bonded to the base by ultrasonic welding, then the bonding process is simple, but the bonding strength is insufficient due to reduced welding area
Solution Approach 1:
The patent transitions from surface bonding (2D) to lateral periphery welding (1D edge bonding), fundamentally changing the bonding dimension. The flange part is welded along its lateral periphery rather than bonding the entire surface, which surprisingly increases the effective bonding area and strength while maintaining manufacturing simplicity.
Solution Approach 2:
The measurement terminal is divided into a shaft part and a flange part with distinct functions. The shaft part inserts into the recessed hole for positioning, while the flange part provides the welding surface. This segmentation allows optimization of each part's function and increases overall bonding strength.
2Volume of moving object
If the welding area is reduced, then the device size is smaller, but the load capacity against axial slipping decreases
Solution Approach 1:
The patent shifts the welding from a reduced surface area to the lateral periphery of the flange part, utilizing the edge dimension rather than reducing the overall device size. This maintains compact dimensions while maximizing the effective welding area along the periphery.
Solution Approach 2:
The patent changes the welding parameter from surface area bonding to lateral periphery length bonding. By optimizing the flange part dimensions and welding along the edge, the load capacity is increased without proportionally increasing the device volume.
3Device complexity
If the measurement terminal is inserted without a recessed hole, then the structure is simpler, but the load capacity in the thrust direction decreases
Solution Approach 1:
The base is segmented to include a recessed hole that receives the shaft part of the measurement terminal. This recessed structure provides mechanical support and increases thrust direction load capacity while adding minimal complexity to the overall device.
Solution Approach 2:
The shaft part of the measurement terminal is nested within the recessed hole of the base, creating a fitted structure that enhances mechanical strength in the thrust direction. This nesting provides support without significantly increasing external dimensions.
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 achieves sufficient bonding strength, reduces noise during current measurements, and increases the accuracy of detection, while also providing reinforcement against vibration-induced failures.
Implementation Method 1
for fixation of the measurement terminal (12) on each base (11), the flange part (12b) is welded (12c) on the lateral periphery thereof
Implementation Method 2
the shaft part (12a) is inserted into the recessed hole (11a, first recessed hole 11a1, second recessed hole 11a2) to be fixed on each base (11)
Data Source
AI summary
A shunt resistor having sufficient bonding strength includes a resistor, a pair of bases which are integrally formed with the resistor so as to sandwich the resistor, recessed holes which are respectively formed in the bases, and measurement terminals which are inserted into the recessed holes and are affixed to the bases. Each measurement terminal has a shaft part and a flange part that protrudes outwardly in the circumferential direction of the shaft part. Each recessed hole is formed to have a diameter smaller than the diameter of the flange part, and the shaft parts are respectively inserted into the recessed holes.