Vehicle Seat Cushion Frame Offset Coupling Member
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Solution Overview
Problem
The existing cushion frame designs for vehicle seats experience stress concentration at the joining area of the bracket and side frame when a large load is applied in the seat front-rear direction, leading to potential deformation and detachment issues.
Innovation Solution
A cushion frame configuration that includes a side frame, a bracket with a fixing portion, and a coupling member offset in the seat width direction, which absorbs energy through deformation modes, reducing stress concentration by distributing the load and applying a moment to twist the bracket, with welding regions extending along the outer periphery to enhance joining resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the bracket and side frame are directly welded together in a stacked configuration, then the manufacturing process is simple, but stress concentration occurs at the joining area when large loads are applied
Solution Approach 1:
A coupling member is introduced as an intermediary component between the bracket and side frame. This coupling member includes a coupling portion that couples to the bracket and a rod portion that extends in the seat width direction to connect with the side frame, thereby mediating the connection and distributing stresses away from the direct joining area.
Solution Approach 2:
The coupling member extends in the seat width direction (lateral dimension) rather than only in the vertical direction. This dimensional change allows the load path to be distributed across multiple dimensions, reducing stress concentration at any single joining location while maintaining structural integrity.
2Device complexity
If the coupling member is positioned directly above the side frame, then the joining structure is compact, but the bracket cannot effectively absorb load energy through deformation
Solution Approach 1:
The coupling member is deliberately positioned offset from the side frame in the seat width direction, creating an asymmetric configuration. This asymmetry generates a moment arm that allows the bracket to absorb load energy through controlled deformation and twisting, improving reliability without significantly increasing overall structural complexity.
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 effectively reduces stress concentration by distributing the load across multiple deformation modes and inhibits excessive torsional stress, improving the structural integrity and welding workability of the cushion frame.
Implementation Method 1
at least a part of energy of the load applied to the side frame is absorbed, for example, in the form of deformation of the bracket due to the parallel load
Implementation Method 2
a moment (rotational force) to twist the bracket is applied to the upper end portion of the bracket through the coupling member
Data Source
AI summary
A cushion frame for use in a vehicle seat includes a side frame extending in a seat front-rear direction, a bracket supporting the side frame and a coupling member. The bracket includes a lower end portion having a fixing portion fixed to a vehicle directly or indirectly. The coupling member is fixed to an upper end portion of the bracket to hold the upper end portion at a position offset in a seat width direction relative to the side frame and to fix the upper end portion to the side frame. A welding region of the coupling member, projected on a virtual plane orthogonal to the seat width direction, extends along an outer periphery of the coupling member in a specified area including an intersection between the outer periphery of the coupling member projected on the virtual plane and a bracket normal line.