Pneumatic Tire Conductive Joint Layout for Low Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for reducing electrical resistance in tires while maintaining low rolling resistance are inadequate, as they either increase electrical resistance or compromise tire performance.
Innovation Solution
A pneumatic tire design featuring conductive members with low volume resistivity exposed on both sides of the rubber chafer and carcass joint sections, forming conductive paths to reduce electrical resistance while maintaining low rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a low-loss rubber composition is applied to case members to reduce rolling resistance, then fuel efficiency is improved, but electrical resistance increases and electricity is not released adequately
Solution Approach 1:
The tire is divided into different functional zones: low-loss rubber composition is applied to the tread portion for reduced rolling resistance, while conductive members are specifically positioned in the bead portions and joint sections to ensure electrical conductivity. This segmentation allows each region to perform its specialized function without compromising the other.
Solution Approach 2:
Conductive members serve as intermediary elements that bridge the gap between the low-loss rubber composition and the requirement for electrical conductivity. These conductive members are strategically placed in the bead portions and joint sections to create discharge paths for electricity while allowing the main tire structure to use low-loss rubber for reduced rolling resistance.
2Reliability
If a high-loss member is used to reduce electrical resistance, then electricity is released adequately, but rolling resistance deteriorates
Solution Approach 1:
Different rubber compositions are applied to different parts of the tire based on local requirements: high-conductivity rubber is used in the bead portions and joint sections where electrical discharge is needed, while low-loss rubber composition is used in the tread portion where rolling resistance reduction is critical. This local differentiation resolves the contradiction by allowing each region to have the properties it needs.
3Reliability
If conductive members are arranged in the tire to reduce electrical resistance, then electricity is released, but structural limitations arise
Solution Approach 1:
The conductive members are merged with the existing tire structure by positioning them within the bead portions and joint sections during the tire manufacturing process. This integration allows the conductive members to become part of the tire's structural framework rather than separate additions, reducing structural limitations and simplifying the overall design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design effectively lowers the electrical resistance of the tire while achieving low rolling resistance, ensuring efficient electrical conductivity and fuel efficiency.
Implementation Method 1
a first conductive member having a volume resistivity of 1 × 10 8 Ω·cm or less, in a joint section of the side rubber and/or that of the rubber chafer
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a pneumatic tire in which the electrical resistance of the whole tire can be lowered even when the rolling resistance is further reduced by further improving the low loss property of a case member of the tire. The pneumatic tire includes: a pair of bead portions (11); a pair of side wall portions (12); and a tread portion (13), which extends between the pair of the side wall portions. In this pneumatic tire, a carcass (1) composed of at least one carcass ply toroidally extending between the pair of the bead portions is used as a skeleton, a side rubber (12G) is arranged on a tire width-direction outer surface of each of the side wall portions, and a rubber chafer (3) is arranged on a tire width-direction outer surface of each of the bead portions. The side rubber and the rubber chafer each include a joint section extending in a tire radial direction, and a first conductive member (6A) having a volume resistivity of 1 × 108 Ω·cm or lower is arranged in at least a part of the joint section of the side rubber and/or that of the rubber chafer.