Conductive Tire Edge Cover Layout for Low-Resistance Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire technologies face a challenge in improving conductivity without degrading manufacturing efficiency, particularly when using low hysteresis loss compositions that can cut conductive paths and exceed electrical resistance thresholds.
Innovation Solution
A tire design with a radially innermost ply covered by a conductive rubber edge cover layer, extending beyond the ply's axial extremity to ensure contact with the carcass, and optionally covering the outer faces, along with conductive paths to the contact face, maintains conductivity while reducing semi-finished products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If low hysteresis loss composition is used to reduce rolling resistance, then fuel efficiency is improved, but conductivity is degraded and electrical resistance threshold is exceeded
Solution Approach 1:
The tire structure is segmented into functional zones: the low hysteresis loss composition is used in the belt plies for rolling resistance reduction, while a separate conductive rubber composition is used in the edge cover layer to maintain conductivity. This segmentation allows each material to optimize its specific function without compromising the other.
Solution Approach 2:
Different rubber compositions are applied to different regions of the tire. The edge cover layer at the radial edges uses conductive rubber composition with high electrical conductivity, while the central belt plies use low hysteresis loss composition. This local differentiation ensures that conductivity requirements are met at critical edges while maintaining low rolling resistance in the tread area.
2Reliability
If additional plies and conductive layers are added to improve conductivity, then electrical resistance threshold is met, but manufacturing efficiency is degraded due to increased number of semi-finished products
Solution Approach 1:
The edge cover layer is merged with the radially innermost ply in the manufacturing process, forming an integrated structure. This combining approach reduces the number of separate semi-finished products that need to be handled and assembled, thereby maintaining manufacturing efficiency while still providing the necessary conductive path through the edge cover layer.
Solution Approach 2:
The edge cover layer serves multiple functions simultaneously: it provides electrical conductivity to meet the resistance threshold, reinforces the radial edges of the tire, and integrates with the ply structure to maintain manufacturing efficiency. This multi-functionality eliminates the need for separate components for each function.
3Reliability
If edge cover layer extends beyond axial extremity of ply to ensure conductive path, then conductivity is improved, but device complexity increases
Solution Approach 1:
The edge cover layer extends in the axial dimension beyond the axial extremity of the radially innermost ply. This dimensional extension ensures that the conductive path reaches the outer surface of the tire at the radial edges, providing effective conductivity without requiring complex multi-layer arrangements or additional components.
Data Source
AI summary
A tire has a tread and a pair of sidewalls extending from each of two axial ends of the tread, at least a radially innermost ply being provided with an edge cover layer made of a conductive rubber composition and covering at least a radially inner face of a radially innermost ply and extending as far as an axial distance L, at least one of the sidewalls extending along with the carcass toward underneath the radially innermost ply as far as an axial distance Le, the axial distance L being greater than the axial distance Le, and the edge cover layer provided with the radially innermost ply having a portion contacting with a carcass, the axial distance L is at least equal to 10.0 mm greater than the axial distance Le.