Pneumatic Tire Tread Web Width Gradient for Crack-Free Molding
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Solution Overview
Problem
Existing pneumatic vehicle tire tread profiles with transverse grooves and connecting webs face challenges in maintaining narrow web widths to prevent cracking during molding while ensuring adequate aquaplaning performance, as narrow webs are prone to cracking and difficult to mold, while wider webs compromise groove depth and aquaplaning ability.
Innovation Solution
Designing a tread profile with webs that progressively decrease in width from the inside to the outside in cross-sectional planes, featuring a monotonically decreasing gradient or parabolic contour, which facilitates easier and crack-free molding, and stabilizes profile block elements for improved handling and stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the web width is kept narrow to maintain high negative profile proportion in transverse grooves, then aquaplaning ability is improved, but the web is prone to cracking and difficult to mold during tire production
Solution Approach 1:
The web width is varied along its radial extent, transitioning from a narrower width at the groove base to a wider width at the outer surface. This parameter change allows the web to maintain adequate negative profile proportion for aquaplaning performance while having sufficient width at the molding surface for easy, crack-free manufacturing.
2Ease of manufacture
If the web width is increased to facilitate molding and prevent cracking, then ease of manufacture is improved, but the negative portion of the transverse groove is reduced, limiting aquaplaning ability
Solution Approach 1:
The web width parameter is changed along the radial direction, being wider at the molding surface for easy manufacturing and narrower at the groove base for adequate aquaplaning performance. This gradient design allows both requirements to be satisfied simultaneously.
3Ease of manufacture
If the web width constantly decreases from inside to outside with straight flanks, then molding is facilitated, but the web may still be prone to cracking and the transition area requires additional rounding
Solution Approach 1:
The web flanks are designed with curvature rather than straight lines, creating a smooth, rounded transition from the groove base to the outer surface. This curved geometry eliminates sharp corners that could cause stress concentration and cracking, while facilitating easy molding without requiring additional rounding operations.
Data Source
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AI summary
The tire has a tread profile comprising grooves that separate radially projecting profile block elements (6) from each other. A rod (8) is formed in one of the grooves, and extended through the groove transverse to a main extension direction of the groove. The rod connects the profile elements with one another and extends from a bottom (10) of the groove till to a radial distance (h1) of greater than zero from an outer surface (9) of the tread profile. The rod is designed with progressively decreasing breadth perpendicular to the main extension direction along a radial extension.