Rotary Structural Body Support for Steering Angle Detection Accuracy
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Solution Overview
Problem
The existing rotary structural bodies in vehicle steering systems suffer from inaccuracies in detecting the rotation angle due to potential fitting gaps between the guide groove and guide projection, leading to free rotation of the steering shaft and reduced detection accuracy.
Innovation Solution
A rotary structural body configuration that includes a rotation body, a detector, and a support with an elastic force greater than the applied force, where the support extends across the circumferential gap between the engaged and engaging portions, ensuring the rotation body follows the rotation shaft accurately, and includes a spring piece to elastically hold the projection, guiding and coupling the rotation body effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a guide groove and guide projection are used to couple the rotation body to the rotation shaft, then the structure is simple and easy to manufacture, but a fitting gap occurs between the guide groove wall and guide projection, causing free rotation and reducing detection accuracy
Solution Approach 1:
A support member is introduced as an intermediary component between the guide groove and guide projection. This support member spans the circumferential gap and provides continuous support, preventing the guide projection from moving freely within the guide groove while maintaining the simple coupling structure. The support member acts as a mediator that eliminates the fitting gap issue without complicating the overall coupling mechanism.
Solution Approach 2:
The support member changes the physical parameters of the coupling interface by providing continuous radial support. Instead of relying solely on the geometric fit between the guide groove and projection, the support member introduces a new parameter - continuous support force - that eliminates the fitting gap and prevents free rotation, thereby improving detection accuracy while keeping the structure simple.
2Measurement precision
If the support member has high elastic force to prevent bending, then the rotation body accurately follows the rotation shaft, but the support member may bend under applied force from the rotation shaft
Solution Approach 1:
The support member's elastic force parameter is optimized to be greater than the applied force from the rotation shaft. This parameter change ensures that the support member maintains its shape and does not bend under normal operating conditions, thereby ensuring accurate transmission of rotational position without compromising the structural integrity of the support member.
3Ease of operation
If the guide portion is separated from the engaging portion by a distance that decreases toward the contact portion, then the rotation body is guided and coupled effectively, but the structure becomes more complex
Solution Approach 1:
The guide portion is designed with local quality variation - the distance between the guide portion and engaging portion decreases at positions closer to the contact portion. This creates a tapered or converging geometry that naturally guides the rotation body into proper alignment during coupling. The local geometric modification provides self-alignment and facilitates coupling without requiring additional complex guiding mechanisms.
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 enhances the accuracy of detecting the rotation angle by preventing backlash and ensuring the rotation body follows the rotation shaft, thereby improving the precision of the steering angle detection.
Implementation Method 1
The support has an elastic force that is greater than force applied to the rotation body from one of the rotation shaft and a transmission member
Data Source
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AI summary
A rotary structural body includes a rotation body (32,54,55) configured to rotate in cooperation with a rotation shaft (13). The rotation body (32,54,55) includes an engaging portion (35;37) engaged with an engaged portion (37;35) arranged on one of the rotation shaft (13) and a transmission member (21) configured to transmit rotation of the rotation shaft (13) to the rotation body (32,54,55). The rotary structural body further includes a detector (51,52) configured to detect a rotation angle of the rotation shaft (13) in accordance with rotation of the rotation body (32,54,55) and a support (40:40a;40b) arranged on the engaged portion (37;35) to extend across a circumferential gap between the engaged portion (37;35) and the engaging portion (35;37).