Pneumatic Tire Bead Durability via Carcass Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radial tires for construction vehicles face challenges in maintaining durability, particularly in the bead portion, due to heavy loads and poor road conditions, leading to potential collapse and failure under usage.
Innovation Solution
The pneumatic tire design includes a pair of bead cores and bead fillers with a carcass layer that extends and folds back, with specific distances and load relationships (a=0.019×x+13.3 and b=0.052×x+21.6) to suppress carcass layer collapse, enhancing durability by reducing shearing and compaction strains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the carcass layer is made stronger to prevent collapse under heavy loads, then the tire durability is improved, but the complexity of the tire structure increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the distances a and b in the carcass layer configuration according to specific formulas (a=0.019×x+13.3 and b=0.052×x+21.6, where x is the specified load). This quantitative adjustment of geometric parameters optimizes the carcass layer's resistance to collapse under heavy loads without adding structural complexity, thereby improving tire durability through parameter optimization rather than structural complication.
2Reliability
If the carcass layer configuration is optimized to reduce shearing strain, then the bead portion failure is suppressed, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise parameter relationships (a=0.019×x+13.3 and b=0.052×x+21.6) that must be maintained during manufacturing. While this does improve bead portion strength by optimizing shearing strain distribution, it simultaneously increases manufacturing precision requirements, as the carcass layer must be positioned and configured to within tight tolerances of these calculated distances to achieve the intended strain reduction and durability benefits.
Data Source
AI summary
When a tire that is mounted on a specified rim, inflated to an internal pressure of 50 kPa, and placed in a no-load state is viewed as a cross-section from the tire meridian direction, a position of 1.30×Hf on an outer surface of a sidewall portion, taking a rim flange height (Hf) of the specified rim as a reference, is defined as a point (P), a foot of a normal line (L) drawn from the point (P) to a carcass line of a main body portion (131) of a carcass layer (13) is defined as a point (M), and a point of intersection of the normal line (L) and a carcass line of a folded back portion (132) of the carcass layer (13) is defined as a point (T). At this time, a distance (a) mm from the point (M) to the point (T), a distance (b) mm from the point (T) to the point (P), and a specified load (x) kN have relationships such that a=0.019×x+13.3 and b=0.052×x+21.6, with a tolerance of not less than 0% and not more than 20%.