Chamfered Sipes with Raised Bottoms for Tire Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Pneumatic tires face a trade-off between steering stability on dry and wet road surfaces, where increasing sipes for improved wet surface stability reduces rib rigidity and thus deteriorates dry surface stability.

Innovation Solution

The design incorporates chamfered sipes with raised bottom portions, where the chamfered portions are shorter than the sipe length, and non-chamfered regions are present alongside, enhancing drainage and block rigidity, while maintaining a minimal chamfered area to improve both dry and wet surface stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large number of sipes are disposed in a tread portion to improve steering stability performance on wet road surfaces, then drainage properties are improved, but the rigidity of the ribs decreases, causing steering stability performance on dry road surfaces to deteriorate

Engineering Contradiction:

Improvesteering stability performance on wet road surfacesVSAvoidrigidity of the ribs

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by providing chamfered portions only at specific locations (leading side and/or trailing side of sipes) rather than uniformly across all sipes. This localized chamfering provides drainage enhancement at critical water ejection points while preserving rib rigidity in other areas. The selective placement of chamfers creates different functional zones: chamfered regions for water drainage and non-chamfered regions for structural support.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements partial action by providing chamfered portions on only some sipes or only at specific ends of sipes (leading side, trailing side, or both), rather than chamfering all sipes completely. The chamfered portion length is controlled to be a specific proportion (0.01 to 0.5 times the sipe length), providing sufficient drainage function without excessive material removal that would compromise rib rigidity.

Inventive Principle:

Principle #16Partial or excessive action

2Reliability

If sipes are chamfered to enhance drainage effect, then steering stability performance on wet road surfaces is improved, but the edge effects may be lost and block rigidity decreases, causing steering stability performance on dry road surfaces to deteriorate

Engineering Contradiction:

Improvesteering stability performance on wet road surfacesVSAvoidblock rigidity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by precisely controlling the dimensions of chamfered portions. The chamfered portion length is limited to 0.01 to 0.5 times the sipe length, and the depth is controlled to be 0.1 to 0.5 times the sipe depth. These parameter constraints ensure that drainage function is enhanced while maintaining sufficient material for block rigidity. The raised bottom portion parameter (protruding 0.1 to 0.5 mm) further optimizes this balance by providing water ejection capability while maintaining structural integrity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses local quality by providing raised bottom portions at specific locations within chamfered portions, particularly at the center or toward the trailing side. This localized reinforcement at critical water ejection points enhances drainage function without requiring extensive chamfering that would compromise overall block rigidity. The raised bottom portion creates a focal point for water ejection while the surrounding material maintains structural support.

Inventive Principle:

Principle #3Local quality

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 configuration enhances steering stability on both dry and wet road surfaces in a balanced manner by improving drainage, removing water films effectively, and increasing block rigidity, thus achieving superior performance in both conditions.

Implementation Method 1

the drainage effect to be enhanced via the chamfered portion

Methodology Applied

Scientific EffectDrainage effect:

Implementation Method 2

with the raised bottom portion formed in the chamfered portion functioning to suppress the deformation of the blocks when the tire comes into contact with the ground, block rigidity to be increased

Methodology Applied

Scientific EffectMechanical support:

Implementation Method 3

a water film can be effectively removed by the edge effect in the non-chamfered regions

Methodology Applied

Scientific EffectEdge effect:

Data Source

PatentUS11524528B2Pneumatic tire

Publication Date: 2022.12.13 THE YOKOHAMA RUBBER CO LTD

AI summary

In a pneumatic tire, a sipe includes an edge on a leading side and an edge on a trailing side; the edge on the leading side and the edge on the trailing side each include a chamfered portion shorter than a sipe length of the sipe; a non-chamfered region in which other chamfered portions are not present is provided at portions facing the chamfered portions of the sipe; a maximum depth of the chamfered portion is less than a maximum depth of the sipe; a sipe width of the sipe is constant in a range from an end portion located on an inner side in a tire radial direction of the chamfered portion to a groove bottom of the sipe; and a raised bottom portion is disposed in at least one section of the chamfered portion.