Current Sensor Coil Mounting with Deformable Locating Pins
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Solution Overview
Problem
Current current sensing devices with multiple coil elements face challenges in precise and economical positioning on substrates, particularly on simple substrates like PCBs, due to limited positioning precision and potential damage during assembly.
Innovation Solution
The use of substrates with specifically designed holes and locating pins on the coil elements, where the pins deform to ensure accurate positioning, allowing for precise alignment and secure mounting without damaging the pins or the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If basic component placement concepts are used to mount coil elements on PCB, then ease of manufacture is improved, but positioning precision deteriorates
Solution Approach 1:
The patent introduces an intermediary mounting structure with locating pins and corresponding holes that act as a mediator between the coil element and the PCB. The locating pins with specific cross-sectional shapes (rectangular, triangular, or oval) engage with matching holes in the mounting structure, providing precise positioning while allowing for controlled deformation during assembly. This intermediary structure enables high positioning precision without requiring complex direct mounting methods on the PCB.
2Reliability
If clearance is increased between connecting pin and PCB hole to reduce stress risk, then reliability is improved, but positioning precision deteriorates
Solution Approach 1:
The patent segments the mounting function into two distinct parts: positioning function performed by locating pins with specific cross-sectional shapes engaging with precision holes in the mounting structure, and electrical connection function performed by separate connecting pins. This segmentation allows the positioning system to achieve high precision through the locating pins while the connecting pins can have larger clearance for reliability, without compromising either function.
3Manufacturing precision
If locating pins are made rigid for precise positioning, then positioning precision is improved, but susceptibility to damage during assembly increases
Solution Approach 1:
The patent changes the geometric parameters of the locating pins by providing them with specific cross-sectional shapes (rectangular, triangular, or oval) that are smaller than the corresponding holes. This parameter change allows the pins to be inserted with controlled deformation or flexibility, enabling precise positioning while reducing susceptibility to damage during assembly. The pins can deform slightly to pass through the holes and then maintain their position, achieving both precision and damage resistance.
Data Source
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AI summary
The present invention relates to a current sensing device, comprising: a substrate (40); and one or more coil elements (30). The substrate comprises a plurality of holes (100) projecting at least part way through the substrate from a first surface of the substrate, wherein prior to a coil element being mounted to the substrate each of the plurality holes has a circular or polygonal cross section. The coil element comprises: a winding body (10, 20); a length of wire (80); and a plurality of locating pins (60). The winding body has an outer surface around an axis of the winding body, and wherein at least a portion of the length of wire is wound multiple times around the outer surface of the winding body in a generally circumferential direction with respect to the axis of the winding body. A first locating pin of the plurality of locating pins projects from the coil element in a direction parallel to a pin axis that is perpendicular to the axis of the winding body, and wherein a second locating pin of the plurality of locating pins projects from the coil element in the direction parallel to the pin axis. Prior to the coil element being mounted to the substrate a cross section of the first locating pin perpendicular to the pin axis comprises first and second outer vertices facing away from the second locating pin, and a cross section of the second locating pin perpendicular to the pin axis comprises third and fourth outer vertices facing away from the first locating pin, and wherein the four outer vertices form a first quadrangle. When the coil element is mounted to the first surface of the substrate the first locating pin is located in a first hole of the plurality of holes such that the first and second outer vertices are in contact with first and second regions on the inside of the first hole and the second locating pin is located in a second hole of the plurality of holes such that the third and fourth outer vertices are in contact with third and fourth regions on the inside of the second hole. Prior to the coil element being mounted to the substrate, first and second circumferential or perimeter points of the first circular or polygonal cross section hole correlate with the first and second regions, and third and fourth circumferential or perimeter points of the second circular or polygonal cross section hole correlate with the third and fourth regions, and wherein the four circumferential or perimeter points form a second quadrangle smaller than the first quadrangle.