Pneumatic Tyre Sidewall Deformation Control
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Solution Overview
Problem
Existing tire manufacturing methods on a drum lead to sidewall irregularities due to uneven reinforcement distribution, particularly at junction zones, causing performance and aesthetic issues.
Innovation Solution
Incorporating a rubberized covering strip with radially oriented reinforcements that extends between specific points on the tire, covering part of the junction zone, to reduce deformation by adjusting its length and width relative to the junction zone, and avoiding contact with the tread reinforcing structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a lap junction is used to connect ply edges, then the connection strength is improved due to large adhesion surface, but the sidewall uniformity deteriorates because of double thickness of fabric causing uneven elongation
Solution Approach 1:
The patent extracts the problematic double-layer fabric from the sidewall region by using a butt junction instead of a lap junction. The ply edges are connected end-to-end at the bead area, eliminating the overlapping section that causes doubled thickness and uneven sidewall elongation. This extraction of the problematic element resolves the contradiction between connection strength and sidewall uniformity.
Solution Approach 2:
The patent segments the tire structure into distinct zones: the bead area where junction occurs, the crown area, and the sidewall area. By confining the junction to the bead region and using a butt junction configuration, the segmentation prevents the junction zone from extending into the sidewall region, thereby maintaining sidewall uniformity while still providing adequate connection strength at the bead.
2Reliability
If a reinforced covering strip is applied to the entire junction zone, then the connection robustness is improved, but the sidewall deformation is aggravated due to additional reinforcement effect
Solution Approach 1:
The patent applies local quality by providing different reinforcement characteristics in different zones. The butt junction provides localized connection strength at the bead area without extending reinforcement into the sidewall zone. This localized approach ensures connection robustness where needed while preventing additional reinforcement from causing sidewall deformation in the crown and sidewall regions.
Solution Approach 2:
Instead of applying reinforcement covering the entire junction zone as in prior art, the patent uses partial action by confining the junction to only the necessary bead area. This partial reinforcement approach provides sufficient connection robustness for the application while avoiding excessive reinforcement that would cause sidewall deformation.
3Ease of manufacture
If the junction zone is left without additional reinforcement, then the manufacturing simplicity is maintained, but the connection robustness deteriorates during conformation
Solution Approach 1:
The patent incorporates the junction design into the initial ply construction phase on the drum. The butt junction is formed as the ply is being wound, with the edges meeting end-to-end at the bead line. This preliminary action during manufacturing ensures connection robustness is built into the structure itself, eliminating the need for subsequent reinforcement operations while maintaining manufacturing simplicity.
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
Significantly reduces sidewall deformation and irregularities, enhancing both the appearance and performance of the tire by maintaining uniformity and minimizing the risk of deformation under inflation pressure.
Implementation Method 1
the connection of the ply edges relies on the adhesiveness of small portions of rubber composition coating the reinforcing elements
Implementation Method 2
applying heat and pressure to 'weld' the area
Data Source
Figure 1~4
Figure 2~3
Figure 5~6
AI summary
A tire (11) comprising beads, each containing at least one circumferential reinforcing structure (20), a crown comprising a reinforcing structure (30) surmounted radially outwards by a tread (40), on either side of the crown, a sidewall (50) providing the connection with each bead, at least one carcass reinforcement (60) extending from one bead to the other, passing through the crown, and anchored to at least one circumferential reinforcing structure (20) in each bead, the carcass reinforcement (60) being made of at least one rubberized layer comprising reinforcements extending substantially radially, i.e., making an angle between 80° and 100° with the circumferential direction, at least one junction zone (70) by overlapping the layer on itself, this zone (70) being oriented substantially radially, at least one overlap strip (80, 81) covering part of a junction area (70),each cover strip (80,81) being made of a rubber composition reinforced by a plurality of reinforcements (95), the reinforcements (95) of each cover strip (80, 81) having a substantially radial orientation, each cover strip (80, 81), viewed in radial section, extending between a point near the axial end of the reinforcement structure (30) of the top and a point located radially inside the outermost axial point of the tire (11).