Torque Detection Device Shared Yoke Cover Assembly
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Solution Overview
Problem
Existing torque detection apparatuses in electric power steering systems have complex configurations with multiple component members and require frequent press-fitting of yoke covers, leading to increased assembly complexity and reduced efficiency.
Innovation Solution
A torque detection apparatus with a simplified configuration using a pair of detection coils wound on reel-shaped bobbins, held by cylindrical electromagnetic yokes, and a shared yoke cover that is press-fit once between the yokes, along with a press-fit regulation portion and phase regulation features to ensure accurate positioning and connection of terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If each coil unit includes a single coil bobbin and a single electromagnetic yoke and a single yoke cover, then the structure is simple and easy to manufacture, but the number of press-fitting operations increases and assembly complexity increases
Solution Approach 1:
The patent combines two separate yoke covers into a single shared yoke cover that covers both electromagnetic yokes simultaneously. This merging reduces the number of press-fitting operations from two to one, simplifying the assembly process while maintaining the structural simplicity and manufacturability of individual components.
2Manufacturing precision
If a yoke cover is press-fit into each electromagnetic yoke separately, then the positioning is precise, but the number of component members increases and assembly time increases
Solution Approach 1:
The shared yoke cover integrates the coverage of two separate yoke covers into one component. This single cover is press-fit into both electromagnetic yokes simultaneously, reducing assembly time while maintaining positioning precision through the shared structure that ensures proper alignment and coverage for both yokes.
Solution Approach 2:
The shared yoke cover serves multiple functions: it covers both electromagnetic yokes, provides positioning references for both coil units, and acts as a single assembly component. This multi-functionality reduces the total number of parts and assembly operations while maintaining the precision required for torque detection.
3Reliability
If multiple yoke covers are used for multiple yokes, then each yoke is independently protected, but the number of parts increases and assembly performance decreases
Solution Approach 1:
The patent merges two separate protection functions into a single shared yoke cover. This unified cover provides independent protection for both electromagnetic yokes through its extended structure, ensuring that each yoke is properly covered and protected while reducing the total number of parts and improving assembly performance by eliminating redundant components.
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 reduces the number of parts and assembly steps, improving the assembly performance and reliability of the torque detection, enabling effective steering assist control in electric power steering systems.
Implementation Method 1
a pair of detection coils configured to change impedances in opposite directions to each other depending on torque generated at a rotation shaft
Implementation Method 2
a yoke cover configured to be press-fit into inner diameters of the cylindrical portions of the two electromagnetic yokes
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
There are provided a torque detection apparatus that can achieve improvements in assembling performance and quality, and an electric power steering apparatus and a vehicle, each having the torque detection apparatus. A torque sensor TS includes a pair of coils (13a, 13b), two coil bobbins (18) around which the coils (13a, 13b) are respectively wound, two yokes (15a, 15b) respectively holding the two coil bobbins (18), and a yoke cover (14) to be press-fit into inner diameters of the yokes (15a, 15b). The yoke cover (14) is positioned to be interposed by the two yokes (15a, 15b) facing each other in an axial direction, and is press--fit into the inner diameters of the two yokes (15a, 15b).