Pneumatic Tire Bead Wire Arrangement for Weight and Durability
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Solution Overview
Problem
Conventional pneumatic tires that reduce weight by omitting bead fillers compromise durability, leading to concerns about tire longevity.
Innovation Solution
A pneumatic tire design featuring bead cores formed by annularly winding bead wires, a carcass layer turned back to wrap the bead cores, and a rim cushion rubber, with a rubber occupancy ratio of 15% or less in a closed region, and specific wire arrangement structures to enhance durability and weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If bead fillers are omitted to reduce tire weight, then tire weight is reduced, but durability deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the rubber occupancy ratio (reducing to 15% or less in the closed region) and the radial height ratio H2/H1 (optimizing to 0.80-3.00). These parameter optimizations allow the tire to achieve weight reduction comparable to omitting bead fillers while maintaining durability through the optimized carcass layer configuration and wire arrangement structure.
Solution Approach 2:
The patent employs composite materials by combining the carcass layer made of fiber-reinforced rubber with steel bead wires arranged in specific patterns. This composite structure provides both the weight reduction benefit (by minimizing rubber in the closed region) and durability (through the strong fiber-reinforced carcass layer and steel wire reinforcement).
2Weight of moving object
If the rubber occupancy ratio is reduced to minimize weight, then tire weight is reduced, but structural integrity may be compromised
Solution Approach 1:
The patent optimizes the rubber occupancy ratio parameter to 15% or less in the closed region formed by the turned-back carcass layer. This parameter optimization, combined with controlling the radial height ratio H2/H1 within 0.80-3.00, maintains structural integrity while minimizing rubber material usage for weight reduction.
Solution Approach 2:
The patent utilizes the curved geometry of the turned-back carcass layer forming a closed region around the bead cores. This curved structural configuration provides inherent strength and stability, maintaining structural integrity even with minimal rubber occupancy in the enclosed space.
3Ease of operation
If the wire arrangement structure is optimized for rim fitting, then rim fitting performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent optimizes the wire arrangement structure by controlling the radial height ratio H2/H1 to be within 0.80-3.00 and the gauge ratio Wh/φ to be within 2.0-15.0. These parameter specifications define optimal wire placement that ensures proper rim fitting performance while providing clear manufacturing guidelines.
Data Source
AI summary
In a pneumatic tire, bead cores have a wire arrangement. In a cross-sectional view in a tire meridian direction, a tangential line and a contact point are defined. The tangential line contacts an innermost layer in a radial direction and the wire cross sections innermost and outermost in a lateral direction in the wire arrangement from a rim fitting surface side. The contact point of the tangent line is on the wire cross section on the outermost side. A gauge Wh in the lateral direction from the contact point to the rim fitting surface and an outer diameter φ of the bead wire have a relationship 2.0≤Wh/φ≤15.0. A radial height H2 of a contact portion between a body portion and a turned back portion of a carcass layer has a relationship 0.80≤H2/H1≤3.00 to a radial height H1 of the bead cores.