Tyre Vulcanisation Mould Radial Sector Alignment
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Solution Overview
Problem
The 'upsetting' phenomenon occurs during the vulcanization and moulding of tyres, where elastomeric material accumulates between adjacent sectors due to tangential and radial motion components of forming elements, leading to humps and noise issues when the tyre is used.
Innovation Solution
Sliding circumferential sectors on sector carriers, guided radially, to ensure precise alignment and penetration into the tyre tread, reducing the angular phase displacement and the occurrence of 'upsetting', thereby minimizing humps and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If circumferential sectors are radially closed during vulcanisation and moulding, then the desired tread pattern and tyre conformation are achieved, but elastomeric material accumulates in the coupling regions between adjacent sectors causing the 'upsetting' phenomenon
Solution Approach 1:
The mould is divided into multiple circumferential sectors that can move independently. Each sector is equipped with radial guides that constrain its movement path, allowing precise control over the closing action. This segmentation enables the forming elements to approach the tyre tread radially without tangential displacement, preventing material accumulation at sector boundaries while still achieving the desired tread pattern through controlled radial closure.
2Productivity
If forming elements are moved tangentially during sector closure, then the sectors can be brought together, but this causes mutual approaching that leads to material displacement and accumulation
Solution Approach 1:
The sector carriers are designed to move dynamically during the vulcanisation process. The carriers can shift position to accommodate sector closure while the radial guides ensure that the forming elements maintain a purely radial approach path. This dynamic adjustment allows rapid sector closure without the tangential motion that would cause material displacement, thus maintaining both productivity and material distribution uniformity.
3Manufacturing precision
If the number of circumferential sectors is increased to reduce angular phase displacement, then the 'upsetting' phenomenon is reduced, but the device complexity increases
Solution Approach 1:
The radial guides are designed as universal components that can be applied to any number of circumferential sectors without changing their fundamental design. Each sector-carrier assembly with its integrated radial guides functions as a standardized module. This universality allows the system to accommodate different numbers of sectors (optimizing angular phase displacement) without proportionally increasing overall device complexity, as the same guide principle repeats across all sectors.
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 solution improves tyre quality by reducing the 'upsetting' phenomenon, resulting in less noise and more even tyre performance, while maintaining a simple and efficient assembly process.
Implementation Method 1
The supplied heat causes cross-linking of the elastomeric material of which the tyre is made
Implementation Method 2
a driving ring axially movable relative to the moulding cavity (8) and having at least one conical surface slidably engaging said circumferential sector carriers (13), so as to determine the radial translation of the circumferential sectors (9)
Data Source
Figure 1
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AI summary
A process and an apparatus for moulding and vulcanisation of tyres for vehicle wheels, wherein a green tyre (7) is positioned on a lower half-shell (4a) of a vulcanisation mould (2). A plurality of circumferential sectors (9) carrying forming elements in relief (11) are engaged by an axial movement into radial guides (26) and radially translated in said radial guides (26) from a first work condition in which the forming elements in relief (11) are radially spaced apart from the radially external surface of the tread band (10), to a second work condition in which the forming elements in relief (11) penetrate at least partly into said radially external surface. Subsequently heat is supplied to the tyre (7) for carrying out vulcanisation of same.