Pneumatic Tire Carcass Layer Folding for Weight and Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires with multiple carcass layers face issues of increased weight and rolling resistance due to high load and internal pressure, leading to separation failures and reduced steering stability.
Innovation Solution
A pneumatic tire design with two carcass layers, where both ends of the inner carcass layer are folded back around bead cores and positioned between the innermost belt layer and the main carcass layer, and the outer carcass layer ends extend outward to overlap bead fillers without being folded back, forming a three-ply structure at the sidewalls for stability while minimizing excess material for reduced weight and rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If three carcass layers are used in the side wall portions, then steering stability is improved, but tire weight and rolling resistance increase
Solution Approach 1:
The patent applies different carcass layer configurations to different regions of the tire. Specifically, three carcass layers are arranged in the side wall portions to ensure steering stability, while only two carcass layers are used in the tread portion to reduce weight and rolling resistance. This regional differentiation resolves the contradiction by optimizing each area for its specific functional requirements.
2Stability of the object's composition
If three carcass layers are used, then steering stability is improved, but separation resistance deteriorates due to increased flexing at layer ends
Solution Approach 1:
The patent implements a localized three-layer structure only in the side wall portions where steering stability is critical, while using a two-layer structure in the tread portion where separation resistance is more important. This spatial differentiation allows the tire to achieve both steering stability and separation resistance by matching the structural configuration to the functional demands of each region.
3Weight of moving object
If the number of carcass layers is reduced, then tire weight and rolling resistance are reduced, but steering stability deteriorates
Solution Approach 1:
The patent strategically places three carcass layers in the side wall portions where steering stability is most needed, while reducing to two layers in the tread portion where weight reduction is prioritized. This selective application of different layer counts resolves the contradiction by ensuring adequate steering stability while achieving weight and rolling resistance reduction.
4Force
If multiple carcass layer ends are disposed at bead portions, then load capacity is maintained, but separation failure occurs due to flexing at these locations
Solution Approach 1:
The patent positions the ends of the third carcass layer specifically in the side wall portions rather than at the bead portions. This localization avoids the high-flexing bead areas where separation failures commonly occur, while still maintaining adequate load capacity through the overall multi-layer structure. The third layer's ends are strategically placed where they provide reinforcement without subjecting them to excessive flexing.
Data Source
AI summary
A pneumatic tire has two carcass layers including carcass cords are laid between a pair of bead portions, bead cores and bead fillers are disposed in the bead portions, and at least two belt layers are disposed on the outer circumferential side of the carcass layers, the tire being characterized in that both ends of the inner carcass layer are folded back from the tire inner side to the tire outer side around the bead cores, and the ends of the folded back portions of the inner carcass layer are disposed between the innermost belt layer and the outer carcass layer, while both ends of the outer carcass layer are disposed so as to pass between a main portion of the inner carcass layer and the bead fillers, and both ends of the outer carcass layer terminate at the bead portions without being folded back around the bead cores.