Vehicle Seat Cushion Hardness Gradient for Rigid Bolsters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle seat assemblies lack a cost-effective and simple method to create rigid inboard and outboard bolster areas while maintaining a soft central portion, which is essential for comfort, durability, and safety.
Innovation Solution
A vehicle seat assembly with a hardness gradient is achieved by incorporating intrusions or protrusions in the foam cushion, creating a 8% to 25% greater hardness in bolster areas compared to the central portion, using a combination of materials like polyurethane foam and trim materials, allowing for improved durability and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the entire seat cushion is made with uniform hardness, then manufacturing is simple, but the bolster areas cannot provide sufficient rigidity for load-bearing while the center portion lacks softness for comfort
Solution Approach 1:
The patent applies local quality by creating regions of different hardness within the seat cushion. Intrusions are placed specifically in the bolster areas to increase local rigidity, while the center portion maintains its original softness. This allows each region to have the mechanical properties needed for its specific function without requiring complex multi-material construction.
Solution Approach 2:
The patent changes the physical parameters of the foam cushion by introducing intrusions that alter the density and hardness distribution. The intrusions create a hardness gradient where the bolster areas have higher hardness (better for load-bearing) and the center has lower hardness (better for comfort), resolving the contradiction between uniform manufacturing simplicity and differentiated performance requirements.
2Reliability
If intrusions are added to create hardness gradient, then comfort and durability improve, but manufacturing complexity increases
Solution Approach 1:
The patent merges the creation of hardness variation with the existing foam molding process. Rather than adding a separate manufacturing step, the intrusions are integrated into the mold design itself, allowing the hardness gradient to be created during the standard foam injection process. This combining approach improves reliability through hardness differentiation while minimizing increases in manufacturing complexity.
3Strength
If harder material is used in bolster areas, then load-bearing capacity improves, but weight and cost increase
Solution Approach 1:
The patent uses intrusions within the foam structure to create regions of varying density. The intrusions in the bolster areas create a more dense, harder foam structure that provides superior load-bearing capacity. This approach achieves the needed strength improvement without requiring a complete replacement with heavier solid materials, as the intrusions work within the existing foam matrix to provide localized reinforcement.
Data Source
AI summary
A method of making a vehicle seat assembly comprising providing a cushion having an “A” surface, a “B” surface, a central portion, and two bolster areas, with each bolster area being adjacent the central portion, the cushion having a plurality of intrusions extending from the “A” surface towards the “B” surface to form a hardness gradient between at least one of the bolster areas and the central portion of between 8% to 25%, securing the cushion to a frame, and covering cushion with a trim member.