Pneumatic Tire Sipe Chamfering for Dry Wet Stability

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Solution Overview

Problem

Conventional pneumatic tire designs face a trade-off between steering stability on dry and wet road surfaces, where numerous sipes improve wet surface stability but reduce rib rigidity and thus dry surface stability, and chamfering techniques often fail to adequately enhance both conditions.

Innovation Solution

A pneumatic tire design featuring sipes with chamfered leading and trailing edges, a non-chamfered region adjacent to each chamfered portion, and intersecting grooves that intersect with the sipes or chamfered portions, optimizing drainage and edge effects to improve stability on both dry and wet surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large number of sipes are disposed in the tread portion to improve steering stability on wet road surfaces, then drainage properties are ensured and steering stability on wet road surfaces is improved, but the rigidity of the rib is reduced and steering stability on dry road surfaces is deteriorated

Engineering Contradiction:

Improvesteering stability on wet road surfacesVSAvoidrib rigidity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by creating different regions within the sipe structure: chamfered portions at the leading and trailing edges for drainage and edge effects, and non-chamfered regions in the middle portions for maintaining rib rigidity. This localized differentiation allows each region to serve its specific function optimally.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The sipe structure is segmented into multiple functional zones: chamfered portions at edges for water drainage and edge effects, non-chamfered portions in the middle for structural support, and intersecting grooves for enhanced drainage. This segmentation resolves the contradiction by distributing different functions to different segments.

Inventive Principle:

Principle #1Segmentation

2Reliability

If chamfered portions are formed in sipes to improve drainage effect and steering stability on wet road surfaces, then wet performance is improved, but the area to be chamfered increases which deteriorates steering stability on dry road surfaces

Engineering Contradiction:

Improvesteering stability on wet road surfacesVSAvoidsteering stability on dry road surfaces

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

Chamfered portions are localized only at the leading and trailing edges of the sipes where drainage and edge effects are most needed, while the middle portions remain non-chamfered to preserve rib rigidity. This localized approach maximizes wet performance benefits while minimizing impact on dry surface stability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of chamfering the entire sipe length, the patent applies chamfering partially only to the edge portions. This partial action provides sufficient drainage and edge effects for wet surface performance without excessively reducing rib rigidity for dry surface stability.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If intersecting grooves are added to improve drainability and steering stability on wet road surfaces, then drainage performance is enhanced, but the tread pattern complexity increases

Engineering Contradiction:

ImprovedrainabilityVSAvoidtread pattern complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The intersecting grooves are integrated with the existing sipe structure, combining multiple drainage functions into a unified tread pattern design. The grooves intersect with sipes to create a network that enhances drainage without requiring separate independent features.

Inventive Principle:

Principle #5Merging (Combining)

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 design enhances steering stability on both dry and wet surfaces by maximizing wet performance during braking and acceleration while minimizing the chamfered area for improved dry surface stability, achieving a well-balanced performance.

Implementation Method 1

improving the drainage effect based on the chamfered portion

Methodology Applied

Scientific EffectDrainage effect:

Implementation Method 2

the non-chamfered region is capable of effectively removing the water film by the edge effect

Methodology Applied

Scientific EffectEdge effect:

Implementation Method 3

having an intersecting groove intersecting with at least one out of the sipe and the chamfered portion enables the drainability to be improved

Methodology Applied

Scientific EffectDrainability:

Data Source

PatentUS11370252B2Pneumatic tire

Publication Date: 2022.06.28 THE YOKOHAMA RUBBER CO LTD

AI summary

Provided is a pneumatic tire including a plurality of main grooves extending in the tire circumferential direction in a tread portion and including a sipe extending in a tire width direction on a rib defined by a main groove, the sipe includes a leading side edge and a trailing side edge, a chamfered portion shorter than a sipe length of the sipe is formed in each of the leading side edge and the trailing side edge, a non-chamfered region including no other chamfered portion is present in a part facing each chamfered portion of the sipe, and the rib includes an intersecting groove intersecting with at least one out of the sipe and the chamfered portion.