Tyre Tread Moulding Element with Pin Cutting Means
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Solution Overview
Problem
Existing methods for manufacturing tyre treads with a cover layer in the grooves face challenges such as cracking and alignment issues due to shear forces, leading to imprecise shape and reduced performance benefits.
Innovation Solution
A moulding element with cutting means comprising a plurality of pins positioned on either side of a blade, which cuts and guides the cover layer into the tread groove during the moulding process, reducing stress concentration and crack initiation risk by distributing the cutting force through multiple pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cover layer is shaped by ribs of a vulcanizing mould using shear force, then the insert is converted into a layer of lesser thickness, but this causes cracking within the insert and makes it more difficult to control the movements of the material
Solution Approach 1:
The single rib is segmented into multiple pins arranged in a matrix pattern. This segmentation distributes the shaping force across multiple contact points, reducing the shear force concentration on any single point of the insert, thereby preventing cracking while maintaining thickness control.
Solution Approach 2:
The invention changes the geometric parameters of the shaping tool from a continuous rib to discrete pins with specific spacing and arrangement. This parameter change allows for distributed force application and better control over material flow, achieving both precision shaping and crack prevention.
2Manufacturing precision
If the insert is shaped by shear force from a rib, then the cover layer thickness is reduced, but the shape and thickness of the cover layer become haphazard
Solution Approach 1:
The rib is divided into multiple pins arranged in a regular matrix pattern. This segmentation provides uniform distribution of shaping forces across the insert surface, ensuring consistent thickness reduction and regular shape formation throughout the cover layer.
Solution Approach 2:
Each pin in the matrix provides localized shaping action with controlled force distribution. The specific arrangement and spacing of pins create uniform local deformation across the insert, resulting in overall uniform thickness and regular shape of the cover layer.
3Ease of manufacture
If inserts are made to align with ribs, then the cover layer can be shaped, but this makes manufacture of the tread more complicated
Solution Approach 1:
The continuous rib structure is segmented into discrete pins arranged in a matrix. This segmentation eliminates the need for precise alignment between inserts and ribs, as the distributed pin array can accommodate minor positioning variations while still achieving uniform shaping of the cover layer.
Solution Approach 2:
The pin matrix structure serves multiple functions simultaneously: it provides shaping action, distributes force uniformly, and eliminates alignment requirements. This multi-functionality simplifies the manufacturing process by removing the need for precise insert-rib alignment while maintaining shaping effectiveness.
Data Source
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AI summary
Moulding element of a mould for moulding and vulcanizing a tyre tread, this tread comprising a tread surface intended to come into contact with the ground when the said tyre is rolling. The moulding element (1) comprising a moulding surface (3) intended to mould part of the tyre tread surface and a blade (5) intended to mould a sipe or a groove in the tread. Indeed, the moulding element comprises two cutting means (7) positioned on either side of the blade(5)at a certain distance from this blade, these cutting means (7) comprising a plurality of pins (9).