Helical Conductive Web in Pneumatic Tyre Tread
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Solution Overview
Problem
Existing methods for producing vehicle tires with electrically conductive tread strips face challenges in achieving optimal driving characteristics while maintaining a secure connection to the road surface, as the wide design required for conductivity reduces the contact area and can lead to instability during production.
Innovation Solution
A method involving the helical winding of ribbon-shaped rubber strips with high electrical conductivity over the circumference of the tire, forming a web that extends radially outwards through a less conductive outer layer, allowing for precise positioning and a narrow contact area with the road surface, thereby optimizing driving characteristics and production accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wide electrically conductive layer is used to ensure good connection to the road surface, then electrical conductivity is improved, but the contact surface area is reduced and driving characteristics deteriorate
Solution Approach 1:
The electrically conductive layer is segmented into a narrow web structure that extends radially through the tread layers, rather than using a wide continuous layer. This segmentation allows the conductive path to maintain electrical connectivity while preserving the contact surface area of the outer rubber layer.
Solution Approach 2:
The conductive element transitions from a two-dimensional wide layer to a three-dimensional radial web structure that penetrates through the tread layers. This dimensional change enables the conductive path to extend vertically through the tire structure while maintaining a narrow horizontal footprint, thus preserving road contact area.
2Area of stationary object
If a narrow web design is used to maintain contact surface area, then driving characteristics are improved, but positioning stability deteriorates
Solution Approach 1:
The web is formed by helical winding of rubber strips around the tire circumference, creating a curved, spiral structure rather than a straight narrow strip. This curved configuration provides geometric stability and resistance to displacement, preventing the narrow web from tilting or shifting during tire operation.
Solution Approach 2:
Multiple helical windings of rubber strips are combined to form the web structure, with successive turns overlapping and merging to create a stable, multi-layered conductive path. This merging of multiple elements enhances the structural stability of the narrow web.
3Manufacturing precision
If helical winding with multiple overlapping turns is used to ensure stability, then positioning accuracy is improved, but production complexity increases
Solution Approach 1:
The helical winding process is self-regulating, where the geometry of the tire itself guides the winding path. The rubber strip naturally follows the helical path around the rotating tire, with the tire's own dimensions and rotation providing the template for precise positioning without requiring complex external guidance systems.
Solution Approach 2:
The complex mechanical positioning system is replaced by utilizing the tire's rotational motion and geometric properties. The helical winding leverages the tire's own rotation and shape to achieve precise positioning, substituting mechanical control mechanisms with a more simple kinematic approach.
Data Source
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AI summary
Process for production of a tread for a tyre - in particular of a pneumatic tyre - with a radially inner layer composed of a first rubber material and with a radially outer second layer composed of a second rubber material and forming the ground-contact surface of the pneumatic tyre, where the first rubber material in particular has higher electrical conductivity than the second rubber material, and where, in the form of a fillet axially dividing the second layer around the periphery of the pneumatic tyre, the first rubber material extends radially outwards through the second layer as far as the ground-contact surface, characterized in that a ply of the first layer composed of a first rubber material and the second layer composed of a second rubber material are constructed radially one on the other, on a rotationally symmetric construction surface, on one of the two axial sides of the fillet (34) to be produced, in each case in a first axially extending region which reaches as far as the position of the fillet, and in that, starting from the other axial side of the fillet (34) to be produced, in a second axially extending region, an axially coherent ply of the first layer is produced via winding, in the manner of a screw thread, of a rubber strip composed of the first rubber material, with a plurality of axially adjacent or at least to some extent axially overlapped windings around the rotational axis reaching as far as the ply previously produced for the first layer in the first axially extending region, whereupon on reaching the ply produced for the first layer in the axially extending region, the rubber strip is further wound in contact with the axial edge firstly of the ply produced in the first region for the first layer and then secondly of the second layer, using a plurality of windings to produce the fillet in the manner of a screw thread and/or of a spiral, radially outwards around the rotational axis as far as the envelope of the tread to be constructed, and then in that, in the second axially extending region, the second layer composed of the second rubber material is constructed axially as far as the fillet (34).