Corrugated Tire Bladder Shoulder Fit
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Solution Overview
Problem
Conventional tire curing bladders fail to apply adequate force and support in the tire shoulder area, particularly for high-performance tires, leading to issues like uneven tire gauge, trapped air, and liner cracking, due to poor fit and insufficient radial stretch and contact pressure.
Innovation Solution
An expandable bladder with a toroidal configuration featuring a pair of opposing annular beads and a waved expansion section with alternating peaks and valleys, which leverages the angled portions to securely fit the tire shoulder and applies controlled contact pressure, minimizing force on the bead area and promoting bead placement retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional smooth bladders are used, then the bladder structure is simple and easy to manufacture, but the bladder cannot fit well into the tire shoulder area and cannot deliver adequate local high radial stretch and contact pressure
Solution Approach 1:
The bladder incorporates a corrugated expansion section with alternating peaks and valleys instead of a smooth surface. This corrugated structure allows the bladder to better conform to the curved geometry of the tire shoulder area, improving fit and enabling adequate radial stretch and contact pressure delivery.
Solution Approach 2:
The bladder features a localized corrugated expansion section between opposing annular beads rather than a completely different structure throughout. This localized modification provides the necessary compliance and fit in the critical shoulder area while maintaining simplicity elsewhere in the bladder structure.
2Force
If conventional bladders are used for ultra-high-performance tires with low aspect ratios, then the bladder structure remains simple, but the bladder contacts the tire crown area at very low inflation pressures generating large friction force that prevents further radial stretching
Solution Approach 1:
The corrugated structure with peaks and valleys reduces the friction force between the bladder and tire crown area by creating a less continuous contact surface. This reduction in friction allows the bladder to achieve the necessary radial stretching without being constrained by excessive friction forces.
Solution Approach 2:
The corrugated expansion section changes the mechanical parameters of the bladder in the shoulder area, providing increased compliance and ability to stretch radially. This structural modification enables the bladder to deliver high radial stretch and contact pressure even in ultra-high-performance tires with low aspect ratios.
3Reliability
If conventional bladders are used, then the bladder structure is simple, but the bladder cannot apply the correct amount of force and support in the tire shoulder area, resulting in bladder related issues and defects
Solution Approach 1:
The corrugated structure improves reliability by enabling proper fit and force application in the tire shoulder area, preventing defects such as uneven tire gauge, trapped air, and liner cracking that occur with conventional smooth bladders.
Solution Approach 2:
The bladder is segmented into distinct functional zones: opposing annular beads for structural support and a corrugated expansion section for compliant force application. This segmentation allows each part to perform its specific function optimally, improving overall reliability.
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 bladder achieves uniform contact pressure and improved fit in the tire shoulder area, reducing defects and enabling efficient shaping and removal, with reduced cycle time and minimal stretching required for insertion and removal, while maintaining memory of the molded shape.
Implementation Method 1
The expansion of the bladder is accomplished by application of internal pressure to the inner bladder cavity which is provided by a fluid such as a gas, hot water and/or steam
Implementation Method 2
fluid such as a gas, hot water and/or steam which also may participate in the transfer of heat for the curing or vulcanization of the tire
Implementation Method 3
fluid such as a gas, hot water and/or steam which also may participate in the transfer of heat for the curing or vulcanization of the tire
Implementation Method 4
the bladder is collapsed, including release of its internal fluid pressure, and the tire is removed from the tire mold
Data Source
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AI summary
The invention relates to an expandable bladder for shaping a pneumatic tire to be mounted inside a tire curing mold, the expandable bladder (100) having a toroidal configuration and having a pair of opposing annular beads, wherein the bladder has an expansion section (130) that is formed from a plurality of waves (126, 128 ,131,132, 134, 136, 138).