Run-Flat Tire Cord Adhesion and Sidewall Rigidity Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Safety tires with side reinforcement face challenges in maintaining adhesive strength between polyester or aramid fibers and rubber, especially under high-load and high-temperature conditions, leading to decreased cord strength and fatigue, and existing solutions like two-bath treatments are costly and inefficient.
Innovation Solution
A pneumatic safety tire design with a carcass ply composed of polyester or aramid fibers coated with a one-bath adhesive agent composition containing a blocked isocyanate, optimized area ratios of side reinforcing rubber, bead filler, and rubber chafer to enhance rigidity and durability, and incorporating protrusion portions for turbulent flow generation to improve heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a two-bath treatment with epoxy-based and RFL-based adhesive agents is used to improve adhesive property between PET and rubber, then adhesive strength is improved, but manufacturing complexity and cost increase due to requiring dedicated two-bath facilities
Solution Approach 1:
The patent combines the epoxy-based adhesive agent and RFL-based adhesive agent into a single bath solution, allowing simultaneous treatment of the cord surface with both adhesive agents. This merging of two separate treatment baths into one reduces facility complexity while maintaining the improved adhesive strength that results from combined chemical treatment of the polyester fiber surface.
Solution Approach 2:
The single bath solution serves multiple functions by containing both epoxy-based and RFL-based adhesive agents that work together to improve adhesive property. This multi-functional approach eliminates the need for separate dedicated facilities for each treatment type, reducing overall device complexity while achieving comprehensive adhesive enhancement.
2Strength
If adhesive agent composition with epoxy compound and isocyanate is formulated to improve adhesive property, then adhesive strength is improved, but cord fatigue property deteriorates due to curing and hardening of the coated cord
Solution Approach 1:
The patent carefully controls the formulation parameters of the adhesive agent composition, specifically the ratios of epoxy compound, isocyanate, and other components, to achieve optimal balance between adhesive strength and cord flexibility. By adjusting these chemical parameters, the coating provides strong adhesion without excessive curing that would harden and fatigue the cord.
Solution Approach 2:
The adhesive agent composition is formulated as a composite material containing multiple components including epoxy compound, isocyanate, rubber latex, and various additives in specific proportions. This composite formulation creates a coating that simultaneously provides strong adhesive bonding and maintains cord flexibility and fatigue resistance through the synergistic effects of its components.
3Strength
If side reinforcing rubber layer is added to improve rigidity and load holding ability, then tire strength is improved, but compression strain concentrates on carcass ply cord between side reinforcing rubber and bead filler, causing cord fatigue
Solution Approach 1:
The patent applies local quality enhancement by treating the carcass ply cord with the specialized adhesive agent composition at the specific location where it contacts the side reinforcing rubber and bead filler. This localized treatment ensures that the cord in the high-stress region has superior adhesive bonding and fatigue resistance, addressing the problem area without requiring changes to the entire tire structure.
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 tire exhibits improved durability, heat-resistant adhesive properties, and extended travel distance capability under low pressure, with enhanced rigidity and resistance to fatigue and heat-induced deformation.
Implementation Method 1
a reinforcing cord of the carcass ply is composed of a polyester fiber and/or an aramid fiber, and coated with an adhesive agent composition in which, on the basis of 100 parts by mass of solid content of a latex, 35 to 100 parts by mass of solid content of a thermosetting resin including a blocked isocyanate is formulated
Implementation Method 2
incorporating protrusion portions for turbulent flow generation to improve heat dissipation
Data Source
Figure 1(a)~1(c)
Figure 2~4
Figure 5~6
AI summary
Provided is a pneumatic safety tire in which the durability is improved by improving the compression fatigue property of a carcass ply cord. The pneumatic safety tire includes, as a skeleton, a carcass 2, and a side reinforcing rubber 4 on a tire width direction inner side thereof in a side wall portion 12. In a cross section in a tire width direction, provided that the area of the side reinforcing rubber is S1, the area of the bead filler 5 is S2, and the area of a rubber chafer 6 arranged on a tire width direction outer side of the bead filler and the bead core is S3, the following expressions (1) and (2) are satisfied: 0.10≤S2+S3/S1≤2.50 0≤S2/S2+S3≤0.9 and a reinforcing cord of a carcass ply is composed of a polyester fiber and/or an aramid fiber, and coated with an adhesive agent composition in whieh, on the basis of 100 parts by mass of solid content of a latex, 35 to 100 parts by mass of solid content of a thermosetting resin including a blocked isocyanate is formulated.