Pneumatic Tyre Belt End Rubber Sheet Stress Relaxation
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Solution Overview
Problem
Pneumatic tires face challenges in enhancing separation resistance at the end part of the belt, particularly with steel belts, where low elastic rubber does not effectively improve separation resistance when used with nylon belts, and varying cross-linking agents in rubber compositions do not significantly enhance separation resistance.
Innovation Solution
A rubber sheet with a lower 100% modulus than the belt tread rubber, blended with 80-140% sulfur and 70-95% carbon black, is arranged near the belt end to cover and relax stress, combined with a multi-layer structure including a protective layer and a border rubber sheet layer, to enhance separation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If low elastic rubber is used to cover the end part of the belt, then distortion concentration is reduced, but separation resistance is not enhanced due to stiffness
Solution Approach 1:
The patent changes the elastic modulus parameter of the rubber sheet to be lower than that of the belt treat rubber (specifically 60-95% of the belt treat rubber's 100% modulus). This parameter change allows the rubber sheet to effectively absorb stress and prevent distortion concentration while maintaining sufficient separation resistance, resolving the contradiction between reducing distortion concentration and enhancing separation resistance.
Solution Approach 2:
The patent applies local quality by placing a rubber sheet with specifically controlled elastic modulus properties at the end part of the belt where stress concentration occurs. The rubber sheet's elastic modulus is locally optimized to be lower than the belt treat rubber, creating a gradient structure that effectively manages stress distribution at the critical end region without compromising overall belt performance.
2Stability of the object's composition
If cross-linking agent amount is varied to reduce rubber elasticity, then separation resistance is scarcely enhanced
Solution Approach 1:
Instead of merely varying the cross-linking agent amount, the patent comprehensively controls multiple parameters including elastic modulus (60-95% of belt treat rubber), sulphur content (80-140% of belt treat rubber), and carbon black content (70-95% of belt treat rubber). This multi-parameter optimization achieves the desired balance between rubber elasticity and separation resistance that cannot be attained by cross-linking agent variation alone.
3Reliability
If end cover rubber is disposed at the end part of the belt, then separation troubles are inhibited, but distortion concentration is not effectively prevented
Solution Approach 1:
The patent specifies that the rubber sheet's elastic modulus should be 60-95% of the belt treat rubber's 100% modulus, creating an optimized elastic gradient. This precise parameter control allows the rubber sheet to simultaneously provide separation resistance and effectively absorb stress to prevent distortion concentration, overcoming the limitations of conventional end cover rubber.
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
This configuration effectively relaxes stress at the belt end, enhances separation resistance, and maintains suitable elasticity to prevent excessive distortion, improving the durability of heavy-duty and aircraft tires.
Implementation Method 1
a rubber sheet having a lower 100% modulus than a 100% modulus of a belt treat of the belt is arranged in the vicinity of an end part of the belt
Implementation Method 2
a stress is relaxed from concentrating at an end part of a belt by a rubber sheet
Data Source
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AI summary
Provided are a separation resistant pneumatic tyre in which a rubber sheet having a lower 100% modulus than a 100% modulus of a belt treat rubber and blended with sulphur in an amount of 80 to 140% based on an amount of sulphur blended in the belt treat rubber is arranged in the vicinity of an end part of the belt, and a production process for the same.