Seat pad
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Solution Overview
Problem
Existing seat pads in vehicles face a challenge in achieving both reduced weight and ride comfort simultaneously, as they often compromise on one aspect for the other.
Innovation Solution
A seat pad design featuring a main component with distinct pressure receiving portions and side components, made from flexible polyurethane foam formed by specific foaming stock solutions containing polyether polyols and isocyanates, with varying molecular weights and functional groups, and different polyisocyanates like MDI and TDI, to achieve optimal density and hardness distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If lightweight materials are used to reduce weight, then weight is reduced, but ride comfort deteriorates
Solution Approach 1:
The patent applies local quality by creating distinct foam density zones within the seat pad. The main first pressure receiving portion has a higher foam density (35-45 kg/m³) while the side components have a lower foam density (25-35 kg/m³). This localized variation in material properties allows the high-density areas to provide structural support and ride comfort, while the low-density areas reduce overall weight, thus resolving the contradiction between weight reduction and ride comfort maintenance.
2Reliability
If foam density is increased to improve ride comfort, then ride comfort is improved, but weight increases
Solution Approach 1:
The patent implements local quality by strategically placing higher density foam only in the main first pressure receiving portion where structural support is needed for ride comfort. The side components use lower density foam to minimize weight. This spatial differentiation of material density allows the seat pad to achieve adequate ride comfort without the penalty of uniform high-density construction, thus resolving the contradiction between ride comfort improvement and weight increase.
3Stability of the object's composition
If different polyisocyanates are used in different portions, then foam density distribution is optimized, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the seat pad into distinct functional portions (main first pressure receiving portion and side components) that are manufactured separately with different foam formulations. Each portion uses a specific polyisocyanate type (MDI for main portion, TDI for side portions) to achieve the desired density characteristics. This segmentation allows for optimized foam density distribution while keeping the manufacturing process manageable through separate molding operations.
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 seat pad achieves ride comfort and stability comparable to existing designs while reducing weight, with the main first pressure receiving portion having a higher foam density than the side components, and the main second pressure receiving portion having a lower hardness, enhancing both seating stability and operational ease.
Implementation Method 1
a main first pressure receiving portion and a main second pressure receiving portion that are provided side by side, wherein the main first pressure receiving portion and the main second pressure receiving portion are a flexible polyurethane foam obtained by foam molding a foaming stock solution containing a polyol, a polyisocyanate, a blowing agent, and a catalyst
Implementation Method 2
the foaming stock solution that forms the main first pressure receiving portion contains a polyether polyol A1 having a weight average molecular weight (Mw) of 3000 to 8000 and 3 to 4 functional groups, and diphenylmethane diisocyanate (MDI)
Implementation Method 3
the foaming stock solution that forms each of the side components contains a polyether polyol A2 having a weight average molecular weight (Mw) of 3000 to 8000 and 3 to 4 functional groups, and tolylene diisocyanate (TDI)
Data Source
AI summary
The present invention is a seat pad (10) that includes a main component (1) having a seating surface and side components (2) disposed on both sides of the main component. The main component includes a main first pressure receiving portion (1a) and a main second pressure receiving portion (1b). The main first pressure receiving portion has a higher foam density than the side components disposed on both sides. The main component and each of the side components are a flexible polyurethane foam obtained by foam molding a foaming stock solution containing a polyol, a polyisocyanate, a blowing agent, and a catalyst. The main first pressure receiving portion contains diphenylmethane diisocyanate (MDI). Each of the side components contain tolylene diisocyanate (TDI).