Alternating Sector Drum for Uniform Tire Component Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drum-based manufacturing processes for annular components of vehicle tires face challenges with high structural rigidity of semifinished products, leading to difficulties in shaping due to non-uniform expansion and excessive stress, which can cause structural discontinuities and non-uniform dilation.
Innovation Solution
The use of an expandable/contractable drum with alternating first and second sectors that expand at different moments, allowing for controlled radial expansion and reduced friction, facilitating uniform shaping by alternating contact points and speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional drum with uniform segments is used for shaping annular tire components, then the drum structure is simple, but the high structural rigidity of semifinished products causes non-uniform expansion and excessive stress leading to structural discontinuities
Solution Approach 1:
The drum is divided into alternating first sectors and second sectors that can expand at different moments. This segmentation allows different regions of the drum to exert expansion forces sequentially on the semifinished product, preventing non-uniform expansion and structural discontinuities while maintaining a relatively simple overall drum structure.
Solution Approach 2:
The drum segments are made radially movable between contracted and expanded positions, transforming the drum from a static structure to a dynamic one. This allows the drum to adapt its expansion characteristics to match the high rigidity of the semifinished product, enabling uniform shaping without excessive stress.
2Ease of manufacture
If the drum segments are made radially movable to facilitate shaping, then the shaping capability is improved, but the processing time increases due to the expansion and contraction cycles
Solution Approach 1:
The alternating first and second sectors expand in a periodic sequence, with first sectors expanding initially and second sectors expanding subsequently. This periodic action enables continuous shaping progress while managing the high rigidity of the semifinished product, optimizing the balance between shaping capability and processing time.
3Device complexity
If the drum expands uniformly to shape the annular component, then the shaping is simplified, but friction between the drum surface and semifinished product causes non-uniform dilation and internal structural tensions
Solution Approach 1:
By segmenting the drum into alternating first and second sectors with different expansion timing, the invention creates controlled variation in the expansion process. This prevents uniform friction-induced dilation while maintaining overall expansion control, eliminating non-uniform dilation and internal structural tensions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A drum (12) comprises first sectors (21a) and second sectors (21b) sequentially interspersed around a central axis (XI) and radially movable starting from a radially contracted condition. With the first sectors (21a) and the second sectors (21b) in the contracted condition, at least one annular semifinished product, comprising one or more reinforcement layers (8a, 8b) that are radially superimposed on each other, is arranged around the drum (12). During the expansion from the contracted condition, the first sectors (21a) and the second sectors (21b) reach at different moments an expanded condition, in which the first sectors (21a) and the second sectors (21b) define an external surface of the drum (12) having a diameter greater than an internal diameter of the semifinished product in order to impose a radial expansion on the semifinished product itself.