Position Detection Device Thermal Deformation Compensation
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Solution Overview
Problem
Temperature-induced thermal expansion and deformation of the encapsulating member and mounting object cause changes in the distance between the detection body and the coil, leading to reduced detection accuracy in rotation angle sensors.
Innovation Solution
A position detection device with a substrate enclosed in a plate-shaped accommodation portion, featuring a connecting part with reduced rigidity compared to the arrangement part, which absorbs deformation due to thermal expansion, thereby minimizing changes in the distance between the detection object and receiving coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate is enclosed in a plate-shaped encapsulating member to protect it, then the substrate is protected, but the encapsulating member warps and deforms due to thermal expansion, causing the substrate to warp and changing the distance between the detection body and the coil, which reduces detection accuracy
Solution Approach 1:
The encapsulating member is divided into a rigid part and a flexible part, where the rigid part maintains structural stability and the flexible part absorbs thermal deformation, preventing substrate warping and maintaining detection accuracy
Solution Approach 2:
Different parts of the encapsulating member have different rigidity characteristics - the rigid part provides structural support while the flexible part accommodates thermal expansion, allowing each region to perform its specific function optimally
2Stability of the object's composition
If the encapsulating member is made rigid to maintain structural stability, then structural stability is improved, but thermal expansion causes warping and deformation, changing the distance between the detection body and the coil, which reduces detection accuracy
Solution Approach 1:
The encapsulating member is segmented into rigid and flexible portions, allowing the rigid part to provide structural stability while the flexible part compensates for thermal deformation, thus maintaining both stability and detection accuracy
Solution Approach 2:
The rigidity parameter of the encapsulating member is varied across different regions - high rigidity in the stable part and low rigidity in the flexible part - to simultaneously achieve structural stability and thermal compensation
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 suppresses changes in magnetic flux, maintaining detection accuracy by reducing deformation of the substrate and coils, thus enhancing the precision of rotation angle detection.
Implementation Method 1
a rotation angle detection sensor detects a rotation angle of the rotor based on a magnetic flux passing through the coil
Implementation Method 2
due to a temperature change in the environment in which the mounting object and the encapsulating member are placed, the mounting object and the encapsulating member may thermally expand and deform
Data Source
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AI summary
A position detection device includes a substrate (100) arranged facing a detection body (30), a transmitting coil (110) formed on the substrate, a first receiving coil (120) and a second receiving coil (130) arranged inside the transmitting coil in a normal direction, and a plate-shaped accommodation portion (500) that accommodates the substrate and has a plate thickness direction in the normal direction. The accommodation portion has an arrangement part (511) in which the substrate is arranged and a mounting part (512) for mounting the accommodation part. The accommodation portion has a connecting part (513) that connects the mounting part and the arrangement part. The connecting part has at least one of two structures: a structure in which a size in the first direction is smaller than that of the arrangement part, and a structure in which a size in the third direction is smaller than that of the arrangement part. The arrangement part has a rigid portion (600, 610, 620, 630, 631, 632, 633, 634, 635, 636, 637) that is formed to be larger in size in the plate thickness direction than other portions of the arrangement part.