Pneumatic Tire Shoulder Land Segmentation for Icy Traction

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Solution Overview

Problem

Conventional pneumatic tires face challenges in achieving effective turning performance on icy and snowy roads due to the deformation of shoulder land portions under load, which leads to inadequate removal of water films between the tire and road surfaces, affecting braking performance and handling stability.

Innovation Solution

The pneumatic tire design incorporates circumferential and widthwise grooves with recessed and raised sections, and indents/lugs on the tire-width-direction lateral surfaces, which connect to widthwise grooves to efficiently discharge water films and increase contact surface area, improving drainage and traction. The tire mold and manufacturing method shape these features to enhance the tire's performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sipes and small grooves are provided in the land portions, then water film removal capability is improved, but turning performance on icy and snowy roads is insufficient due to shoulder land deformation

Engineering Contradiction:
Improveturning performanceVSAvoidtread structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The shoulder land portions are segmented into multiple functional zones: first land portions with conventional sipes for general water removal, and second land portions with recessed/raised sections and indents/lugs specifically for shoulder water film removal. This segmentation allows each zone to address specific turning performance requirements while maintaining overall structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different tread structures are applied to different regions of the tire: the first land portions use conventional siping patterns, while the second land portions at the shoulders use recessed/raised sections with indents/lugs. This local differentiation optimizes water film removal specifically where shoulder deformation occurs during turning, without complicating the entire tread structure.

Inventive Principle:
Principle #3Local quality

2Reliability

If recessed sections and raised sections are added to shoulder land portions, then water film removal capability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvewater film removal capabilityVSAvoidmolding complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The recessed sections, raised sections, and indents/lugs are integrated into a single molded tread structure rather than being separate components. This merging of features into one molding operation simplifies manufacturing while achieving the complex water film removal functionality needed for improved turning performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The second land portions with recessed/raised sections and indents/lugs serve multiple functions: they remove water films from the shoulder contact patch, provide structural support during turning deformation, and maintain tread integrity. This multi-functionality reduces the need for additional separate manufacturing steps.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If indents/lugs are provided in the second land portions, then traction on icy roads is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvetraction performanceVSAvoidindent/lug dimensional precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The indents/lugs are designed with specific dimensional parameters (depth, width, spacing) that optimize traction on icy surfaces. By carefully controlling these parameters within defined ranges, the design achieves reliable traction performance while maintaining feasibility for standard manufacturing tolerances.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The indents/lugs are pre-formed during the tire molding process rather than being added subsequently. This preliminary formation ensures consistent dimensional precision across all tires while simplifying the overall manufacturing process, as the features are created in the same operation that forms the tread itself.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2143571B1Pneumatic tire, tire mold, and method of manufacturing pneumatic tire
Publication Date: 2012.02.22 THE YOKOHAMA RUBBER CO LTD
  • EP2143571B1 patent drawingFigure 1
  • EP2143571B1 patent drawingFigure 2
  • EP2143571B1 patent drawingFigure 3~4

AI summary

A pneumatic tire includes a tread that has: land portions formed and segmented by a plurality of circumferential grooves extending in a tire circumferential direction and by a plurality of widthwise grooves (22) extending in a tire width direction; and sipes formed in contact patches of the land portions (23). The pneumatic tire includes: recessed sections (groove-bottom recessed sections) (61) that are formed in tire-width-direction lateral surfaces (23b) of the land portions (23) provided in tire-width-direction outermost parts, so as to connect to the widthwise grooves (22); and indents/lugs (7) that are formed in bottom surfaces of the recessed sections (61) such that indents/lugs thereof are arranged alternately and continuously in a linear manner.