Bead Reinforcing Cord Layout for Lightweight Racing Tires
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pneumatic tire weight reduction techniques compromise tire rigidity, leading to deteriorated grip performance and durability, particularly in racing tires.
Innovation Solution
A pneumatic tire design featuring a pair of bead portions with a bead core, a carcass extending between them, and a bead reinforcing cord layer, where the carcass is turned up around the bead core, and the bead apex rubber and reinforcing cord layer are strategically positioned to enhance bending rigidity and durability while reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of sidewall portions is reduced to decrease tire weight, then the tire weight is reduced, but the rigidity of the tire is decreased
Solution Approach 1:
The invention applies local quality by concentrating rubber material specifically in the bead apex regions (where it is most needed for structural support) while reducing material in other areas. The bead apex rubber portions are positioned at specific radial heights (15-25% of section height) to provide localized reinforcement that maintains overall tire rigidity while minimizing total material usage and weight.
Solution Approach 2:
The invention uses composite materials by combining rubber compounds with different complex elastic moduli in specific configurations. The bead apex rubber portions use compounds with optimized elastic properties (E*1 and E*2 with specific relationships) to create a composite structure that achieves high rigidity in critical areas while keeping overall weight low.
2Weight of moving object
If the turned-up height of the carcass ply is lowered to decrease tire weight, then the tire weight is reduced, but the rigidity of the tire is decreased
Solution Approach 1:
The invention maintains carcass ply turned-up height in critical bead regions to preserve structural rigidity while allowing weight reduction in non-critical areas. The bead apex rubber portions are strategically positioned to compensate for any reduction in overall carcass height, providing localized reinforcement where rigidity is most needed for cornering performance.
3Weight of moving object
If the tire weight is reduced for racing applications, then the unsprung mass is reduced, but the grip performance and durability may deteriorate
Solution Approach 1:
The invention ensures reliability by concentrating high-strength rubber material with optimized elastic properties in the bead apex regions, which are critical for grip during cornering. The specific positioning (radial height 15-25%) and compound selection (with complex elastic moduli E*1 and E*2 meeting specific relationships) ensure that weight reduction does not compromise the mechanical properties needed for reliable performance under severe racing conditions.
Solution Approach 2:
The invention uses composite rubber compounds with specifically engineered elastic properties to maintain durability and grip performance. The relationship between complex elastic moduli E*1 and E*2 of different rubber portions is optimized to ensure that the tire maintains its structural integrity and grip characteristics even with reduced overall weight, enabling reliable racing performance.
Data Source
AI summary
A pneumatic tire comprises a carcass, a bead apex rubber, and a bead reinforcing cord layer. The bead apex rubber has a radially outer edge positioned at a radial height of 15% to 25% of the tire section height. The bead reinforcing cord layer comprises an axially inner first part disposed on the axially outside of a carcass ply main portion, and an axially outer second part disposed on the axially inside of a carcass ply turned-up portion. The radially outer edge of the axially outer second part is radially outwardly spaced apart from the radially outer edge of the carcass ply turned-up portion by at least 5 mm.