Pneumatic Tire Bead Core Wire Array for Rim Fittability
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Solution Overview
Problem
Conventional pneumatic tires that reduce weight by omitting the bead filler often experience deteriorated rim fittability, affecting assembly and performance.
Innovation Solution
A pneumatic tire design featuring a bead core with a specific wire array structure, a carcass layer turned back to form a rim cushion rubber, and a predetermined gauge change rate to ensure rim fittability while minimizing weight, by optimizing the contact points and gauges in the rim fitting portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the bead filler is omitted to reduce tire weight, then the weight of the tire is reduced, but the rim fittability deteriorates
Solution Approach 1:
The patent applies local quality by creating a specific wire array structure in the bead core with different wire arrangements in different regions. The wire cross-sections are positioned to create predetermined gauges (G1, G2, Gm) that control local deformation characteristics during rim assembly, ensuring adequate rim fittability in the bead region while maintaining overall weight reduction
Solution Approach 2:
The patent changes physical parameters by defining specific gauge measurements (G1, G2, Gm) and their change rates (ΔG1, ΔG2, ΔGm) during rim assembly. By controlling these dimensional parameters and their deformation rates within specific ranges, the patent ensures proper rim fittability without requiring bead filler, thus resolving the contradiction between weight reduction and rim assembly performance
2Reliability
If the rim fitting pressure is increased to ensure rim fittability, then the rim fittability is improved, but the tire rim assembling workability deteriorates
Solution Approach 1:
The patent controls the deformation behavior during rim assembly by specifying that the change rates of gauges G1, G2, and Gm (ΔG1, ΔG2, ΔGm) should be in a specific range. This parameter control allows the bead core to deform appropriately during assembly, ensuring adequate rim fittability while preventing excessive rim fitting pressure that would degrade assembling workability
Data Source
AI summary
In this pneumatic tire, the bead core has a predetermined wire array structure obtained by arranging wire cross-sections of bead wires in a cross-sectional view in a tire meridian direction. The following are defined in the wire array structure: a tangent line that contacts, from the side of a rim fitting face, an innermost layer in the tire radial direction and the wire cross-section on the innermost side and the outermost side in the tire lateral direction; contact points of the tangent line with respect to the wire cross-sections on the innermost side and the outermost side; a middle point of the contact points; and gauges in the tire radial direction from the contact points and middle point to the rim fitting face. In this case, the change rates of the gauges before and after rim assembly each are in the range of 10% to 60%.