Vehicle Seat Load Detection Bracket With Press-Fit Fixing
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Solution Overview
Problem
Existing load detection devices for vehicle seats face issues with dimensional differences between fixing portions and holes, leading to internal stress and inaccurate load measurement when washers are integrally connected with an amplifier.
Innovation Solution
A load detection device with a strain generating body, strain gauges, and a unique fixing mechanism using a bracket member with a press-fit fixing member to accommodate dimensional errors, ensuring accurate load measurement without internal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the first and second washers are integrally connected by means of an attachment portion for attaching an amplifier, then the device complexity is reduced, but dimensional differences between the two fixing portions and the fixing holes cause internal stress generation and inaccurate load detection
Solution Approach 1:
The bracket member is divided into a first fixing portion and a second fixing portion that are separately formed, allowing each to be independently adjusted and fitted to the corresponding fixing holes without dimensional constraints from integral connection
Solution Approach 2:
A press-fit fixing member is introduced as an intermediary component between the second fixing portion and the second fixing hole, enabling dimensional error compensation through press-fit connection while preventing internal stress transmission to the strain generating body
2Measurement precision
If the washers are separately and independently configured, then accurate fitting to fixing holes is achieved, but the device complexity increases due to multiple independent components
Solution Approach 1:
The first fixing portion and second fixing portion are integrated into a single bracket member structure, reducing the number of separate components while maintaining the ability to accommodate dimensional variations through separate formation of the fixing portions
3Ease of manufacture
If the fixing portions are forced to be press-fitted into the corresponding fixing holes despite dimensional differences, then assembly is simplified, but internal stress is generated at the sensor board and load detection accuracy deteriorates
Solution Approach 1:
The press-fit fixing member allows for parameter adjustment in the connection between the bracket member and the strain generating body, accommodating dimensional variations without forcing the connection, thereby preventing internal stress generation
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
The solution allows for accurate detection of loads applied to a vehicle seat occupant by minimizing internal stress and ensuring proper fitting of components, enhancing the reliability of load measurement systems.
Implementation Method 1
a strain gauge that generates strain in accordance with a load applied by an occupant seated on the seat for the vehicle
Data Source
AI summary
A load detection device includes a strain generating body having first and second holes at first and second ends of the strain generating body, a strain gauge attached on the strain generating body, first and second fixing members having first and second middle shaft portion press-fitted into the first and second holes, respectively, and having first and second end shaft portions protruding from the first and second middle shaft portions, respectively, a bracket member having first fixing portion including a first fixing hole into which the first end shaft portion is press-fitted, and a second fixing portion, integrally connected to the first fixing portion and including a second fixing hole into which the second end shaft portion is inserted with a clearance therebetween, a press-fit fixing member press-fitted onto the second end shaft portion, and a connecting shaft integrally connected to the strain generating body.