Heavy-duty tire middle rib segmentation for wet cornering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Heavy-duty pneumatic tires face challenges in cornering performance on wet road surfaces while maintaining uneven wear resistance, with existing designs either compromising on wear resistance or experiencing uneven wear issues.

Innovation Solution

The tire design features a tread portion with main grooves and ribs, including a crown rib with crown sipes, a middle rib with middle sipes and a shallow groove, and lateral shallow grooves that divide the middle rib, enhancing edge components for improved wet performance and cornering without increasing uneven wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a groove or sipe having an edge component in the tire circumferential direction is added to improve cornering running performance on wet road surface, then cornering running performance is improved, but uneven wear is caused

Engineering Contradiction:
Improvecornering running performanceVSAvoiduneven wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The middle rib is segmented by the circumferential middle shallow groove into an inner portion and an outer portion, creating a structured division that allows different zones to serve different functions while maintaining overall rib integrity and reducing uneven wear

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The middle shallow groove has different dimensions (smaller depth, larger width) compared to middle sipes, and is positioned specifically to provide edge components for cornering performance while its unique geometry prevents the harmful uneven wear effect

Inventive Principle:
Principle #3Local quality

2Reliability

If the middle rib is divided into inner portion and outer portion by circumferential middle shallow groove, then edge component is enhanced for improved wet performance, but rib rigidity may be reduced

Engineering Contradiction:
Improvewet performanceVSAvoidrib rigidity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The middle shallow groove is designed with specific parameter relationships (smaller depth, larger width compared to middle sipes) that optimize the balance between providing edge components for wet performance and maintaining sufficient rib rigidity through controlled structural modification

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3363655B1Heavy-duty pneumatic tire
Publication Date: 2019.05.29 SUMITOMO RUBBER INDUSTRIES LTD
  • EP3363655B1 patent drawingFigure 1
  • EP3363655B1 patent drawingFigure 2
  • EP3363655B1 patent drawingFigure 3

AI summary

A heavy-duty pneumatic tire comprises a crown rib 4C and a middle rib 4M. The crown rib 4C is provided with crown sipes 6 crossing the crown rib 4C. The middle rib 4M is provided with middle sipes 7 crossing the middle rib 4M and a middle shallow groove 9 having a smaller depth and a larger width than the middle sipes 7. The middle shallow groove 9 comprises a circumferential middle shallow groove 10 extending in a tire circumferential direction and lateral middle shallow grooves 11 extending from an axially inner side edge (Ema) of the middle rib 4M to the circumferential middle shallow groove 10 so as to terminate at a position thereof.